When this topic comes up I notice two schools of thought, both of which are equally wrong:
"Batman has beaten Superman before so he isn't that big a deal" (you'd be surprised how often I see this); or
"I hate Batman because DC writes him as an unstoppable genius perfect badass Batgod and to keep that image they write stories where he humiliates other characters like Superman, god how I hate Batman and his fanboys"
Two points: Batman has never, and I do mean never, beaten Superman in canon content. Even with prep, his chances of beating Superman are not exactly ideal. To that end, I've compiled a list of all their encounters in both canon and non canon material. I'm pretty sure this is every fight they've ever had, but there might be one or two that I missed. This is mainly so people can shut up about Batgod beating Superman or Superman being a loser because Batman has supposedly beaten him based on one or two out of context scans they've seen floating around on the internet.
Note: I am not doing this because I hate Batman. Far from it, I love Batman. Nor am I doing this to uphold Superman's honor or anything that pointless, anyone with common sense should know that Batman isn't beating Superman anytime soon. This is just to put all the facts out in the open.
Post-Crisis skirmishes between Superman and Batman:
Batman's trying to bring the Joker to justice for beating Jason to death and blowing him and his mother up, but Joker was conferred diplomatic immunity by Iran (don't ask), so Superman's telling him to calm down since there's nothing he can do. Batman gets angry, and...
End result: Batman punches Superman and is saved from being Oracle before Oracle because Superman rolled with the punch. Advantage Kal-El.
The Dark Knight Returns (non canon)
The Superman of the TDKR universe is considerably weaker than the New Earth version (he was almost killed by a nuke). A fight where Superman is holding back considerably, exposed to kryptonite courtesy of Green Arrow, and more concerned about Batman's health than his own, ends with Superman holding Batman's body after he suffers a near fatal heart attack.
End result: Note how Batman claims that he's "the one man who beat you". Batman can claim whatever he wants. Even with one-sided prep and backup, the fight didn't end with him holding Superman's seemingly dead body, did it? Advantage Kal-El.
The infamous Tower of Babel incident, where Ra's al Ghul steals Batman's contingency plans for bringing down the JLA and employs them against the various members. Turns out Batman's plan for taking down a rogue Superman was a specially engineered form of red kryptonite that wreaked havoc with Superman's ability to metabolize sunlight.
End result: This is probably the only canon incident that could be used to claim any kind of win for Batman over Superman. And it's not even a direct encounter. A lot of people claim that since Ra's could easily pull this off, Batman should also be able to. Couple of points regarding that:
- Ra's has resources that dwarf Batman's. In The Resurrection of Ra's al Ghul he told Tim Drake that comparing the Wayne fortune to his own wealth would be akin to comparing a drop of water to the ocean or something along those lines. He also has an army at his beck and call that he can deploy to achieve his desired effect. It would be much easier for Ra's to do something like this than it would be for Batman.
- Batman is a member of the League, and thus under constant scrutiny from the people he's plotting against. Ra's operates in the shadows, he does not have to worry about Superman finding out about what he's up to. Especially since he's not even a League villain.
I guess if you stretch a little, Batman is potentially capable of this. Very well, advantage Batman.
The Dark Knight Strikes Again (non canon)
That image of Batman punching Superman in The Dark Knight Returns is spammed mercilessly on the battle forums despite the fact that Batman didn't even win. He actually fought Superman and won in the sequel to TDKR. This example isn't as well known as TDKR because TDKSA sucks the big one. Seriously, it is unbelievably bad. But anyway:
End result: With the help of the Flash, the Atom, Green Arrow and years of prep, Batman manages to defeat Superman in a direct encounter. Even though Superman just wanted to talk. Still, this is the only instance of Batman ever beating Superman in any published content, but it's not canon.
Probably the most famous fight between the two. Or given that the only image from this fight that ever sees the light of day is the one where Batman punches Superman, it's probably the most famous fight between the two that no one bothers actually reading before posting "LOL SUPERMAN GOT PUNCHED OUT BY BATMAN, SO HULK SMASH PUNY KRYPTONIAN".
End result: First and foremost, this was written by Jeph Loeb. 90% of the things Jeph Loeb writes require a liberal suspension of disbelief, even for comics. He thinks a tiny piece of kryptonite stuck in a ring is enough to lower Superman's durability to the point where Batman can make him bleed. Why Superman even gave Batman that ring, I'll never be able to figure out. If he ever actually went rogue, a kryptonite ring is not going to stop him from simply nuking Bruce with his heat vision. But ok, I'll play along. Note three things: that Batman himself says that if Superman wanted he could kill him with superspeed, that Batman himself says that if he continually punches Superman every bone in his hand will shatter, and that Batman himself says that Superman is holding back as much as he can while fighting Ivy's control. Even so, after hitting Kal with all the electricity in Metropolis, the battle still comes down to Catwoman putting Lois in danger, forcing Superman to break Ivy's control and save her instead of beating Batman to death with a car. Look at that scan. If Catwoman had been a few seconds late, Superman would have brought a car weighing several tons down on Bruce's head, and exactly what could he possibly do about that? Advantage Kal-El.
Superman: Red Son (non canon)
Another Elseworlds story (and a really good one at that). If you haven't read this, you should.
End result: Batman tying up Wonder Woman is ludicrous in itself, which is probably why it happens off-panel. Batman's prep in this situation isn't really his own, the idea of red solar lamps came from Lex Luthor. Batman just provided the venue. Anyway, he defeats a powerless Superman until Wonder Woman summons all her strength to snap the lasso and eliminate the lamps, restoring Superman to full power. Faced with Superman who actually has his powers, Batman quickly decides that suicide via explosion is the most prudent option available to him. Advantage Kal-El.
The first of a series of fights between the two in this series. Here Superman and Batman fight an alternate future version of Superman. I've included this because technically, it's still Superman vs Batman in canon content.
End result: Evil Supes backhands Batman and is about to throw a car at him, something Bruce a) cannot do anything about, and b) cannot survive. He runs out of time before that happens and fades away to his own timeline. Advantage evil Kal-El.
Adventures of Superman #642
Superman is mind-controlled by Max Lord and placed in an illusion where he thinks he's fighting Darkseid (he says it's Ruin, but that might simply be an error), but in reality he's fighting Batman. He's enraged because he saw Darkseid kill Lois in the illusion, so he's taking it out on Batman.
End result: While fighting off the Watchtower's defenses, Superman nearly murders Batman, who is saved by the intervention of Wonder Woman. Advantage Kal-El. Duh.
Bats is possessed by the Kryptonite Man. That's right. He's literally glowing with kryptonite.
End result: While literally glowing with kryptonite, Batman still loses to Superman. Advantage Kal-El.
Here Batman was under the control of an alien life form called the Blackrock. He had super powers. Legit super powers!
End result: With legit superpowers, Superman still beat him so hard the Blackrock got scared and abandoned him. Advantage Kal-El.
Justice League #2
This fight is the first face-to-face encounter between Superman and Batman post-Flashpoint. I've only included the Batman stuff since the rest of the fight is mostly GL and Flash, so it's irrelevant.
End result: Batman throws literally everything he has at Superman and it doesn't do squat. Who do you think has the advantage here?
Batman: The Dark Knight #5
This is their most recent fight, and already the single image of Batman punching Superman is circulating everywhere as if that's what the fight actually was. Batman is on Bane's new Venom, and with it he somehow hits Superman hard enough to make him bleed. That in itself is PIS, mainly because if this new Venom amps your strength to the point where you can hurt a Kryptonian, then Batman should have been splattered across the wall when Clayface and Bane hit him while they were on the drug. Towards the end of the fight, Batman starts channeling Frank Miller, so Superman goes like:
End result: Even with the PIS strength and durability increase, Superman still wins with one punch. Advantage Kal-El.
So there you have it. The only instance of Superman ever losing to Batman in a direct encounter is a non canon incident where Batman had years of prep and three other heroes helping him. In canon content, Batman's had all kinds of amps and still lost to Superman every time.
Am I saying it's impossible for Batman to ever beat Superman, no matter what the circumstances are? No. I'm just saying it's extremely unlikely. Odds are that in 99% of their encounters, there's only going to be one real outcome.