This is a concept that originated with @shootingnova where I will be ranking the best lightsaber duelists in descending order, and also providing arguments for why they should fit. Now, of course, this list is not a statement of fact with the exception of some characters who are factually stated to be among the best. That said, I will be arguing with evidence, so that will hopefully give my verdicts more weight. Now I stress that these lists will be divided between Sith and Jedi, and that they pertain to lightsaber skill only. Things like Force power and physical stats don't factor in, except when they are contextually important to character victories (which will in turn likely cause those same characters to rank lower).

Update: Due to so many characters sharing one tier/spot (especially where the Jedi are concerned), I decided to alter the set-up of this list a bit. Also added some character images to brighten it up a bit.

With that, out of the way, let's begin:

Sith:

1. Darth Sidious: This should be obvious. Besides it's being pretty much canon fact, the evidence speaks for itself: stalemating Yoda, stalemating a voraciously amped Mace Windu, curbstomping Kit Fisto, casually besting Darth Maul and Savage Opress at the same time when obviously toying with them, besting DE Luke, etc. etc. Palpatine is also cited to know all of the different lightsaber styles, which is a requirement of his chosen form (Juyo) anyways. Further indication of his skill can be seen in how he trained Maul to be the excellent swordsman that he is, so that alone would indicate that he knows his stuff. And also all of his feats above, those too.

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2. Darth Caedus/Darth Krayt (Tie): For Caedus, his fighting against Legacy Era Luke alone is a clear indicator of skill. True, he has some low showings here and there, but they're exactly that: low showings (and honestly, his fight against Jaina's not that much of a strike against him, when one considers all of the context surrounding that fight). Fighting against Luke is proof enough that Caedus is one of the best of the best in Sith lightsaber duelists.

And what of Krayt, you ask? Simple: his multiple good showings against Cade Skywalker, someone who has evidenced Darth Maul-level skill multiple times. Krayt was doing well against him whilst being at essentially death's door thanks to his infection. After being cured of it, he was even more formidable, easily mopping the floor with Cade. I'd call making a Maul-level duelist look foolish to be a pretty good indicator of skill. A level of skill that frankly not even Dooku possess. Hence, I put Krayt here.

3. Darth Tyranus: Considering the sheer volume of feats he has, most of which against opponents with feats of their own, this should be obvious. Factually beating Mace Windu at least once, fighting evenly with him on another occasion, defeating General Grievous, repeatedly defeating Asajj Ventress before and after she improved, repeatedly beating Obi-Wan, repeatedly beating/stalemating CW Anakin, fighting evenly with RotS Obi-Wan, giving RotS Anakin a good fight, beating Sora Bulq and Thome together, fending off Ventress and two Nightsisters with lightsabers while drugged and blinded, etc. Really, Dooku's list is astonishing and exceptional both. Again, not just the large number of opponents he's beaten or stalemated, but how nearly all of them have feats of their own makes it even more impressive, and should leave little doubt in anyone's mind that Dooku is among the best.

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4. Post ANH-Vader/Dark Side Anakin (Tie): Each iteration of Vader is as skilled as the other. DS Anakin was stalemated by Obi-Wan yes, but because of context. Prior to his duel with Obi-Wan, Anakin casually bested Cin Drallig while both distracted and handicapped, killed Serra Keto, and killed most of the other Jedi in the Temple besides. All of his pre-DS showings would also remain valid. As for Vader, he too has bested featless/bottom-tier characters, such as Sa Cuis, and characters who were good by reputation (The Dark Woman and Roan Shyre). In addition, the fact that he is an improved version of a Vader who already showed he could have an extended fight with an amped TPM Darth Maul, an incredible dueling feat. And that was before Vader's prime. Vader at his peak (which is RotJ) was able to duel evenly with his son, who himself had improved significantly from his TESB iteration. Now before people say "But Anakin beat Dooku!", that was owing to advantages over the Count that neither Anakin nor Vader would necessarily have against other opponents. Their skill levels are right below Dooku's but close enough so that their skills in conjunction with their advantages would grant them the win (and did in Anakin's case). But in terms of raw skill, Vader and DS Anakin are marginally below Dooku.

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5. TPM Darth Maul/CW Darth Maul/Lumiya the Dark Lady/ANH Darth Vader (Tie):

• ANH Vader and TPM Maul: A Vader who was pretty much his ANH iteration (as it was the same year), being able to last an incredible length of time against an amped Darth Maul (albeit taking a few hits here and there) should be proof enough of how close in skill Maul and pre-prime Vader are. Yes, Maul won the duel in the end, but again, he was amped to a much greater extent than Vader was, and yet Vader still gave him a very long, drawn-out duel, to the point that even the watching Dark Side acolytes conceded that the duel was closer than they thought it would be. And their other feats support their being close to one another. Maul killed Qui-Gon and was beating Anoon Bondara to the point that he threw the fight, Vader killed the Dark Woman and Roan Shyre, and of course fought evenly with Ben Kenobi. Maul's killed bottom-tier Jedi, Vader's done the same, as well as killing Sa Cuis, who's no better or worse. Both have fought evenly with a version of Obi-Wan not in their prime (before it in CW Obi-Wan's case, after it in ANH Obi-Wan's case). Not really seeing much disparity here.
• CW Maul: People sometimes assume that CW Maul is better than TPM Maul, but that's really only true in respects to Force Power. TPM Maul is actually more agile, at least compared to CW Maul with his "chicken legs". Concerning everything else, especially dueling skill, there isn't much disparity. Killing Qui-Gon is comparable to dueling evenly with CW Obi-Wan, and all of Maul's other victories are against bottom-tier Jedi of about the same level of unimpressiveness, save for Anoon Badara, who Maul was beating prior to TPM, and another Jedi good by reputation named Jun-Fan, who Maul slew during the Clone Wars. Again, not seeing much disparity here. Both versions of Maul are equally skilled, and Pre-TESB Vader is comparable to both of them.
• Lumiya: She was able to soundly beat RotJ Luke when he was unfamiliar with her Light Whip, and even after he became familiar with it Lumiya was still able to give him a good fight, which shows very clearly a high level of skill.

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6. Darth Plagueis/Darth Tenebrous/Tulak Hord (Tie): With these characters, it's less tangible feats that make them good and more other things.

• Plagueis: He did beat Darth Venamis, which is noteworthy because Venamis was in essence Plagueis' doppelganger. Like Plagueis he had been trained by Tenebrous and had been taught to fight in the very same way. So it says a lot about Plagueis' ability to adapt that he could still overcome Venamis in combat, and fairly soundly at that. Furthermore, he possessed a wealth of knowledge on dueling skill and it can also be inferred from his training Palpatine to be the absolute best lightsaber duelist in the history of the Order that he is himself skilled.
• Tenebrous: He ought to be roughly equal to Plagueis since he was also heavily implied to be superior to Venamis and also trained Plagueis to be the good lightsaber duelist that he is. There is also his being stated by Plagueis/the narrator of the novel to have "loved saber dueling" and thus gone out of his way to excel in it (whereas Plagueis conversely, hated dueling). That Tenebrous would also have access to a fair wealth of knowledge (including in saber dueling) would make his being a good lightsaber duelist likely.
• Tulak Hord: For the Sith who was, along with Ajunta Pall and Freedon Nadd one of the very first Sith to wield a lightsaber, Kreia (in a statement that's authenticity has been confirmed by lead writer of KotoR II Chris Avellone) said that if either she or Meetra Surik (albeit Meetra not at her peak) were to face a master of Tulak Hord's time and skill in lightsaber combat, she would find that she and Kreia would be "but children playing with toys" in comparison. Now, pre-prime Meetra and Kreia not exactly being lightsaber aficionados keeps this accolade from making Tulak and his fellow Ancient Sith the absolute best of the best, but it is still a good accolade, since it suggests he would be able to curbstomp duelists of Kreia and pre-prime Meetra's level, and very few lightsaber duels are ever a straight up curbstomp (even many of Maul and Vader's featless victims, for instance, put up a bit of a fight). So the accolade is, while often overblown, still a good indicator of substantial skill. As far as I'm concerned, all three of these duelists are right below Maul, Lumiya, and ANH Vader in skill, being inferior only by a tiny margin.

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7. Ajunta Pall/Freedon Nadd (Tie): Placed here (and right below the above characters in skill) because the accolade given to Tulak would also logically apply to these characters as well, since they're from around the same time as Tulak Hord and both used a lightsaber in addition to other weapons. It would also apply to Naga Sadow, Marka Ragnos, and Ludo Kressh, but as none of them actually used lightsabers, they don't make this list. Their intrinsic skill level should still be about here or the next tier up though. Especially since Ajunta Pall also has the feat of personally slaying over a dozen Jedi at Corbos. I'd call that a fine skill feat myself.

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8. Darth Malgus/Exar Kun/The Emperor's Wrath/Ulic Qel-Droma (Tie):

• Exar and Ulic: Considering that Kun and Qel-Droma had an hour-long stalemate and also that Kun sensed Qel-Droma as a rival (though it may have been rival in respects to Force Power), the two's being equals in dueling should be self-evident.
• Malgus: His slaying the likes of Kao Cen Darach and Ven Zallow (the former done before his prime) are comparable to Kun's killing Vodo Siossk Baas. Outside of these victories, Malgus also twice beat Satele (albeit iterations of Satele before her prime), but it's not as though anyone else Kun and Qel-Droma beat in dueling were terribly impressive either. Furthermore, Kun's attacking his victims with a hitherto unseen weapon likely contributed to the ease of his victories, whereas Malgus and Qel-Droma attained victories over featless opponents without any such advantage. So ultimately, Malgus is comparable to the Tales of the Jedi Sith pair.
• The Emperor's Wrath: Beating Darth Baras (or at least stalemating Baras long enough for him to be drained of his Force power) is actually a good feat in and of itself, as Baras fought evenly with Angral, who himself has some mild feats. That he tired Baras out would seem to invalidate the showing, but he tired Baras out in respects to Force power, not dueling skill. Not only that but the sheer number of opponents the Wrath beat elsewhere is also noteworthy. And given the Wrath (and Sith Warriors in general) predilection for saber dueling, it's safe to assume that, N-Canon game mechanics aside, the Wrath's many victories were still largely owing to saber skill and not Force power. What's also noteworthy is that the Emperor's Wrath beat many of their opponents while still relatively inexperienced.

9. Darth Bane

At his peak, he was challenging Zannah when bloodlusted, with her only barely keeping him at bay. This would also be an improved version of the Bane who gave Kas'im (a duelist good by reputation and technical skill) a solid fight, meaning Bane at his peak would likely be above Kas'im.

10. Savage Opress: Even granting that a lot of Savage's success was owing to superior strength rather than superior dueling skill, he's still not totally inept in this regard. While his stalemating Anakin and Obi-Wan at once was him in a Force Rage and thus not indicative of his standard level of skill, he was earlier able to kill a Jedi without a lightsaber (using a vibroaxe instead), which makes the otherwise strength-reliant victory more impressive. He also dueled evenly with Plo Koon before resorting to superior strength to rip off his breather mask. I'd still place Savage below Plo on the account of the latter's fight with Ventress, but Savage's showing is still decent. He also held his own against Adi Gallia (who briefly contended with General Grievous) before once more using superior strength to pull a win. So, definitely reliant (perhaps too reliant) on strength, but still a credible lightsaber wielder.

Honorable Mentions:

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• Darth Venamis (Not pictured): Was able to give Darth Plagueis a fight, and was trained by Darth Tenebrous in such a way that he was more or less Plagueis' doppelganger, so he ought to be worth mentioning based on that.
• Darth Revan: Prior to reaching this point in his life, he slew Mandalore the Ultimate (who one-shotted Jedi Malak), and is responsible for the loss of Malak's jaw. However, how close or not close a duel the latter was (assuming there even was a duel at all) is ambiguous.
• Lord Kallig: As either Darth Nox or Darth Imperius he/she has some lightsaber fights here and there, but they obviously rely much more heavily on Force power, and their only dueling victories are almost entirely against fodder anyway.
• Darth Zannah: Besides one or two victories over bottom-tier Jedi, she also held her own against a bloodlusted Darth Bane, which is a solid showing.
• Kas'im (Not pictured): Sirak and the other students at the Academy on Korriban were in awe of his skill, and his knowing every single lightsaber form denotes not just technical knowledge and skill but also versatility. He also managed to overwhelm/beat Darth Bane, albeit Bane many years before his prime. Still good though. May just break onto the Top 10 list.

Jedi:

1. NJO Luke Skywalker: While this iteration of Luke was mostly fighting Yuuzhan Vong and not lightsaber duelists, he is a superior version of New Republic Era Luke, who showed he could contend with Palpatine at his peak. So going by that, it's safe to infer that Luke at his peak would have improved in lightsaber dueling, and should be more comparable to Palpatine. And that's more than enough to reach the number one spot.

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2. Amped Mace Windu/Yoda (Tie): Both fought evenly with Darth Sidious, and Yoda actually disarmed him in the RotS junior novelization, so the two's being this high up should be obvious.

3. New Republic Era Luke Skywalker: Again, NR-Era Luke was able to contend with Palpatine, but of course he lost. Still, the fact that he could contend with him for any length of time (and honestly gave a better performance than Kit Fisto did), and also that he would likely be a slightly more skilled version of his already formidable RotJ iteration, means NR Luke ought to rank about here.

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4. RotJ Luke Skywalker/Mace Windu (Tie): Mace Windu has already fought evenly with Dooku, and they are considered equals and rivals. That Mace has fought evenly with someone Dooku beat with difficulty due to knowing how he would fight (Grievous) further points in the direction of them being equals. What has Luke done to put himself on the same par as Mace? Simple: fighting evenly with his father when the latter was at his peak and when Luke didn't even want to fight his father. And in fact, Luke got the upper hand at different points in their duel, and Vader was fearful that Luke could actually beat him. Yes, Dooku is a better swordsman than Vader, but only marginally, and in any event, fighting evenly with Vader when not wanting to fight him and going by other evidence likely being marginally above him, is just as good as being a perfect equal to a slightly better duelist. So near as I can tell, Luke as of this point is just as good as Mace. Beating Lumiya with difficulty should also be comparable to beating Asajj Ventress, and keeping back Flint when not wanting to fight him should be comparable to handling Quinlan Vos when not even trying. If Luke is below Mace, it's only by the very slimmest of margins.

5. RotS Anakin Skywalker: Anakin at this point was able to beat Count Dooku of course, albeit owing partly to the advantages of Djem So and superior strength. Still, those bits of context hardly invalidate the feat outright, and it does suggest that Anakin's base skill at this point in time is almost equal to Dooku, since those few advantages tipped the scale enough to allow him to win. That he's an improved version of the Anakin who's already achieved a string of victories would also be worth noting.

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6. Kit Fisto/Agen Kolar/Saesee Tiin/Legacy-Era Jaina Solo/RotS Obi-Wan Kenobi (Tie):

• Jaina: Kyp and Jaina fought evenly with each-other, so we know they're about on the same level, though not necessarily perfect equals. Jaina also has a very erratic fighting style that is atypical of most Jedi and thus could give her an edge over most Jedi in a duel. She was able to (albeit with assistance from Luke and later her opponent being injured) hold her own against Darth Caedus, and even if we write that off as a low showing for Caedus, fighting evenly with Warmaster Tsavong Lah while immobilized and soundly trouncing amped Dark Siders are good showings in their own right, and should make Jaina (and by extension Kyp) comparable to...
• Kit Fisto: Casually scrapped a trio of magnaguards and was beating General Grievous. Even granting that Shii-Cho factored into these accomplishments, some intrinsic skill had to be present as well. He is also recognized, along with Agen and Tiin (who will be discussed shortly), one of the best lightsaber duelists the Jedi Order ever produced. Quite the accolade.
• RotS Obi-Wan: Like Kit, he also beat/stalemated General Grievous on the account of his lightsaber form giving him an advantage and in fact did better against Asajj Ventress than Kit Fisto has (again though, Shii-Cho factors in, this time as a disadvantage). RotS Obi-Wan could also duel fairly evenly with Count Dooku, who beat him by superior Force power, not superior dueling skill (though he does have that, just not to a gross degree).
• Saesee Tiin: To compare to Obi-Wan's above showings, Saesee Tiin stalemated Mace Windu, showing he's right below him in skill, and Agen Kolar curbstomped Quinlan Vos about as effortlessly as Mace Windu did, which suggests a comparable level of skill. And again, Agen Kolar and Saesee Tiin are both also considered two of the absolute best lightsaber duelists the Jedi Order ever produced. So in all, Agen, Saesee, and Obi-Wan should all be about equal, and also in turn equal to the other two Jedi on this tier.

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7. Eeth Koth/Kyp Durron (Tie): Kyp Durron's being here has already been kind of explained on the account of his stalemating Jaina, albeit Jaina not yet in her prime, but at the same time Kyp may or may not have been holding back. He also has victories against other opponents (such as Vong warriors). With Eeth Koth though a lot of people will likely be scratching their heads wondering why he of all people makes it this far up. The reason for it is his successfully stalemating General Grievous. Yes, Grievous is better (as suggested by how he was steadily forcing Eeth Koth back), but the difference in skill is marginal, not exponential. And being able to hold out against Grievous is a good showing. As to the inevitable "but that was TCW Grievous, and he sucks!", this is only true in respects to physicals. TCW Grievous' dueling skills are really not inconsistent with other iterations of him barring one low showing against Ahsoka Tano and that's it. Other than that, none of TCW Grievous' duels are inconsistent with the way he's been depicted elsewhere. So Eeth Koth's holding out against him is a fair showing. He's smack-dab in-between the characters right above and right below, being very close in skill to all of them.

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8. CW Anakin//CW Obi-Wan Kenobi/Plo Koon/Ki-Adi-Mundi/NJO Kyle Katarn/The Hero of Tython/ANH Obi-Wan/TESB Luke/Mara Jade Skywalker (Tie):

• TCW Anakin and Obi-Wan: Most tend to assume Anakin to be a better swordsman than Obi-Wan, and if we're talking about the AotC or RotS iterations, this assumption would be correct. However, looking at their respective showings, the Clone Wars iterations of Anakin and Obi-Wan seem to be about even. Both have had similar success against Asajj Ventress, and their duels outside of their fights with Ventress are also comparable. Obi-Wan's stalemated Darth Maul repeatedly, Anakin's stalemated a slightly better duelist (Count Dooku) with a Djem So advantage. Obi-Wan's beaten Savage Opress, Anakin before reaching this level of skill stalemated Nejaa Halcyon and slew numerous Dark Acolytes. Not seeing a whole lot of disparity here. Yes, Anakin is better than Obi-Wan if we look at either their AotC or RotS iterations, but Anakin and Obi-Wan c. the middle of the Clone Wars are equals going by the evidence.
• Plo Koon: Plo has stalematedAsajj Ventress just as Obi-Wan and Anakin have, which indicates a similar level of skill. He only lost to Savage Opress due to the latter's ripping off his breather mask, a strength dependent victory rather than a skill dependent one. Prior to Savage resorting to superior strength, Plo was keeping him at bay. So Plo should be comparable to TCW Obi-Wan and Anakin as a duelist.
• Ki-Adi-Mundi: Briefly contended with General Grievous despite extremely negative circumstances (fatigued, had not faced anything like Grievous and his erratic fighting style before, had a form disadvantage). Had it been a fresh Mundi who was more acquainted with GG's fighting style, Mundi would have done even better, which should put him at around Obi-Wan, Anakin, and Plo's level.
• NJO Kyle: I'm mostly going with the notion that he would have improved form his New Republic era iteration, who achieved a string of victories against various bottom-tier characters, several of whom he bested years before his prime. So an improved version of that Kyle should be comparable to the other characters here.
• The Hero of Tython: He/she gets a spot here because of the sheer number of bottom-tier/slightly-above-bottom tier characters that they beat, some of whom they beat while still relatively inexperienced (including when wielding a training lightsaber rather than proper one).
• ANH Obi-Wan and TESB Luke: The former fought evenly with Darth Vader while the latter contended with a better Darth Vader for an extended period and even managed to land a glancing blow on him. That should easily make him comparable to a version of Obi-Wan who stalemated a slightly inferior swordsman and a version of Anakin who stalemated a slightly better swordsman with a form advantage.
• Mara: Her beating Vong becomes more impressive when one remembers when she beat an esteemed Vong warrior under negative circumstances (had never encountered a Vong before and was also injured). She also beat Alema Rar. She also sparred evenly with Corran Horn under negative circumstances, and perhaps most impressive of all, dueled evenly with Lumiya (who even Luke was challenged by).

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9. Qui-Gon/Luminara Unduli/Barriss Offee/AotC Anakin/Nejaa Halcyon/NR-Era Kyle Katarn/Saba Sebatyne/Revan/Meetra Surik (Tie): Basically, to sum it up quickly:

• Qui-Gon: Beat Anoon Bondara and gave a slightly injured Darth Maul a good fight two times.
• Luminara: Gave Ventress a good fight, and actually lasted a little longer against her than Qui-Gon did against Maul. Tempted to rank her higher up.
• Barriss: Gave TCW Anakin a good fight and beat Ahsoka
• AotC Anakin and Nejaa: Stalemated each-other repeatedly, with Anakin also pressing Dooku despite losing (though Djem So did factor in), fought evenly with a pre-prime Asajj Ventress (who also contended with Dooku), and slew various Dark Acolytes, including Count Dooku's doppelganger and a pair of Dark Acolytes that attacked him at once.
• NR Kyle: All the Dark Jedi he beat, several of whom were taken out before he had reached his prime, either overall or for this version of him. He also killed multiple Shadowtroopers, who, while not skilled duelists at all, did have Cortosis armor that would have made them more resistant to lightsaber strikes.
• Saba: Kept at bay an enraged Kenth Hamner when not actually wanting to fight him, and beat him on multiple occasions prior, showing she's pretty clearly superior to him. And Kenth is not a fodder character, having himself bested Yuuzhan Vong warriors.
• Revan: Per Drew Karpyshyn Revan prefers Force combat over saber dueling (and looking at his concrete feats this is true). However, despite this, and also the fact that Revan's overall skill level is extremely vague and difficult to pin down due to the ambiguous circumstances of many of his victories, he did at least manage to beat Mandalore the Ultimate years before his prime (and Mandalore one-shotted Jedi Malak), slew amped Royal Guards (who are supposed to be capable of killing low-tier Sith), and was able to at least duel evenly with an amped Darth Malak, though how much or how little of his victory over Malak was owing to superior dueling skill is unclear. But he had his lightsaber drawn come the battle, so it can be assumed that he could at least defend himself from Amped Malak's attacks. Besides that, there is also his first fight with Darth Malak that cost Malak his jaw (before either one was at their peak), and his fight with Bastila, which I would argue was probably mostly a lightsaber duel, for the following reasons: the fight takes place on a fairly narrow catwalk, and it begins with Revan and Bastila in close proximity to each-other, meaning it is very unlikely to me that they would not resort immediately to lightsaber combat. And the fact is, saber combat or no, Revan was able to keep back an amped (and steadily more enraged) Bastila at bay when not even wanting to fight her (as he was trying to redeem her the whole time). If we interpret this as being mostly a lightsaber duel, then it's a strong indicator of skill, especially since he had also by then fought through a large number of other foes. Now I will concede that it's not definitive that it was mostly a lightsaber duel, but there is some evidence to suggest that it might have been. And if it was, then it is a very good indicator of skill, and along with everything else should put him about on Meetra's level.
• Meetra Surik: Most of the characters Meetra bet were pretty much fodder, but as the old saying goes, "a little's better than none". Besides that, Meetra also has some technical knowledge/skill on the account of knowing multiple lightsaber forms. And, she did manage to beat multiple Dark Siders on both The Ravager and Malachor V. Given the intense Dark Side nature of both worlds, it's safe to assume that all of her opponents in both of these locations (including the Sith Triumvirate) would be augmented. That makes Meetra's dueling with them more impressive.

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10. Aayla Secura/Corran Horn/Ven Zallow (Tie): Rounding up the Top 10 on the account of...

• Aayla: Beating Aurra Sing (albeit with difficulty), and fighting evenly with Quinlan Vos even when he had the advantage of knowing how she would fight due to being her former master. And Aurra Sing has victories over her own, meaning she is not a fodder character.
• Corran Horn: He's admitted to being below Mara Jade before (and their feats support this), making his placement here logical. For feats he's beaten the Yuuzhan Vong commander Shedao Shai. For my money, not too far below the characters in the number 9 spot.
• Ven Zallow: He gave Darth Malgus a good, drawn out fight while also killing Sith Warriors that ran at him during the duel on the side. Malgus also considered him to be the only Jedi in the temple worthy of his attention.

Honorable Mentions:

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• Cin Drallig: Honestly, I'm reluctant to even list him as this. Sure, sources have put him above Shaak Ti, but that's not actually saying much, and his remarkably poor performance against a very handicapped (and distracted) Anakin shows clear as day that he's not THAT great a duelist, and really nowhere close to the level of skill that is often attributed to him.
• The Dark Woman: While she got overwhelmed by pre-prime Vader in saber combat pretty quickly, that was a Dark Woman who was very old and almost assuredly past her prime. Furthermore, Vader had a tremendous strength advantage. It can be assumed that a Dark Woman still in her prime would have done better. She also trained Ki-Adi-Mundi to be the duelist he is/was, and it can be inferred from that she is herself somewhat skilled (at least when again, it's her in her prime).
• Anoon Bondara: Mostly good by reputation, but he did hold out against Darth Maul for a while, albeit being on the defensive for most of it.
• Roan Shyre (Not pictured): Like Anoon, he was good by reputation, and also held his own against (but ultimately lost to) a Sith of substantial dueling skill (and one who was about equal to Maul per his fight with him).
• Satele Shan: Twice contended with Darth Malgus, including when both were before their prime. She did also clash blades with Darth Baras, but the exchange was too brief to count for much. She did also contend with Revan at his peak in saber combat, though she was amped by her Battle Meditation at the time, and the fight was pretty brief.
• Kao Cen Darach: Not only bested Darth Vindican, but showed some technical knowledge/skill due to being able to effectively dual wield a double-bladed lightsaber in a tandem with a regular one.
• Vodo-Siossk Baas: While the comparisons to Yoda are laughably (and I mean laughably) overblown, Vodo did train Kun to be the excellent lightsaber duelist that he is, and it can be inferred from that (as well as his being able to successfully use a stick in place of a lightsaber) that he is himself somewhat skilled. That he could also with this stick contend with Kun even when Kun was using a weapon he'd never seen before (a double-bladed lightsaber) is also a clear indicator of skill.
• Quinlan Vos: Bested some fodder characters here and there (Tol Skorr and Kadrian Sey namely). Also fought evenly with both Aayla Secura and Tholme on different occasions, though in both cases there was the fact that Vos and his opponent would have been intimately familiar with one another's fighting styles due to Tholme training Vos and Vos training Aayla.