I love how people want the movies to be exactly like the comics. *Rolls Eyes* 
 
They took the core elements of the Green Lantern mythos, and sewed something new and original from it. Why do you want to see a rehashing of the same stories you already know? Take bits and pieces of those old stories and make something new. Movies 2 and 3 should NOT be Sinestro Corps War and Blackest Night respectively. Don't shoehorn in the Antimatter Universe or the Blackest Night prophecy or the entire emotional spectrum. Star Sapphire and the original Predator could work. Atrocitus could work, but the Blue Lantern Corps, most of the Red Lantern Corps, and ESPECIALLY the Indigo Tribe could NOT fit into a movie, even if there's more than a trilogy. 
 
By all means, have Sinestro recruit a few more lanterns for his coup, but keep him as the only one with an actual Yellow Ring! That's why he would be a credible villain. Keep the focus in space, give more screen time to Kilowog and Tomar-Re, maybe a select few others and have them participate in the final battle with Sinestro's Squad. Put some emphasis on Hal's distance from Carol while he's in space. Set up Star Sapphire for the third movie. 
 
Have Star Sapphire in the third movie, maybe don't let Hal know it's Carol at first. Put in The Predator. Free Carol. 
 
THEN for a fourth OR instead for the third would be when Hal could start getting into the darker side of the corps. Bring in Atrocitus. He's just broken free from the Sciencells. Who is this mysterious baddie? What's that he's saying about the Guardians? Hal investigates. Hal uncovers the secrets of the Manhunters and the massacre of Sector 666. 3 or 4 movies in, now that Hal is in tune with the corps is the right time to have him gain doubts, not from the very beginning. 
 
ALTERNATIVELY Larfleeze could be used. Greedy being from the forbidden sectors storms across the universe to satiate his hunger. Although actually since he has an army of his constructs he could be the biggest of the movie villains yet, and potential for a 5th film if the others all go through. Or even just an alternative idea for the 3rd or 4th. The point is, Sinestro Corps is just too big for the second movie. Sinestro and a potential coup? That works. Even the Red Lantern Corps wouldn't be great for a movie. Atrocitus would be more credible mostly solo, especially if it worked out the way I suggested. But they should try to set him up on his own, try not to go too Red Lantern or else people will say it's too much like Sinestro, just another color to fight. The Predator works differently, and Larfleeze technically does too, so it works better. And out of all of those, Larfleeze would be the biggest threat. 
 
Finally, NO NO NO NO NO to Emerald Twilight. Yes, Emerald Twilight was epic and awesome. But this movie is trying to appeal to a mainstream audience to bring them in. Mainstream would not accept their big commendable superhero doing such a huge 180…. 
Scratch that, it MIGHT work. ONLY if Atrocitus AND Larfleeze get movies, because THEN Hal would have sufficient enough disgust for the Guardians for such a path to be even conceivable for him. That would be a good way to introduce a new lantern of Earth, probably Kyle. But A LOT of the story would have to be changed, but it MIGHT work.

Agreed, though I assumed everyone wanted the next movie to be loosely based upon the Sinestro Corps War. Trying to make the movie like the comics wouldn't work imo.
 
Now that they've introduced Oa and the basic concepts, I see no reason why the structure of a supposed sequel would be erratic like it was with this movie. One thing they've gotta avoid is cramming too much content into it. I think they should do what you said in the 3rd paragraph regarding Sinestro, have Carol shafted for the most part, but put the Predator in, and sneak in a short Star Saphire scene at some point - but it shouldn't be focused on in this movie. With all the negative (albeit uninformed) backlash regarding not using John Stewart, I'm thinking they could bring him in, and have as an ally of Hal's alongside Tomar-Re, Kilowag, and some others in the final battle scene

@The Mighty Monarch: Forget about the comics. Even for a  movie, it was pretty bad. 

"I love how people want the movies to be exactly like the comics. *Rolls Eyes* 
 
They took the core elements of the Green Lantern mythos, and sewed something new and original from it. Why do you want to see a rehashing of the same stories you already know? Take bits and pieces of those old stories and make something new." 
 
totally totally agree. I think for a comic book movie it was extremely similar to the comic, if it was more like the comic, it would BE the comic. 
 
but you go on to mention more movies, even a fifth. very little movie series even make a fifth sequel, and seeing as how badly gl did at the box office, i think the second will be the last.

I'm talking in hypotheticals here. If Spider-Man 3 hadn't been so bad, they probably could've gotten to 5 movies, I heard they were originally planning to go to 6. I'm just saying IF they plan to go that far, that's probably the best route. In my little dream world of cotton candy clouds where Batman and Robin doesn't exist, Mosaic was never cancelled, and bacon is good for your heart; Green Lantern would make it to 5 movies and that's how they would go.  
But on the off chance that GL2 blows 1 away, there's always a shot.

It was a failure not because of unfaithfulness (in fact, it was probably among the most accurate CBMs so far), but because it was a bad movie.

I believe there is no possible way to make a Green Lantern movie that would make everyone happy. He isn't Batman or Superman whose origin story can be told in 15mins. For what it was I was very happy with it. I would've loved to seen the Manhunters in the sequel but because of the video game I doubt that will happen. Mongul is always a possibility setting up for the destruction of Coast City later on. I do like the idea of putting Star Sapphire in the third movie I'm just not sure on what to do for the second movie.

more line for other Lanterns, visiting other sectors of the Universe, new Lanterns it has t be better than the first one

It's almost a guarantee that something so timeless in one sense, that with its great following and is nearly at the end of its run, should remain timeless and ongoing in another. But it's never quite the same and it shouldn't be, because transitioning from paper to film also guarantees elements will be omitted and reconfigured for a larger audience. If people have an issue with the first film and they think a sequel will fill in the gaps, then completely scrapping the sequel and starting fresh might work out better for everyone.

"A sequel is an admission that you've been reduced to imitating yourself."
-Don Marquis

i actually like this movie. I was against Ryan Renolds as Hal Jordan and i thought the graphics were ok at best but after see the movie i think they did a descent job with it. I think the only down fall to the movie was the villains. They kind of sucked. I liked the fact that Parallax was a Guardian that was over come by fear. I think that would work well in the comics as well. I heard the woman (cant think of her name) Carol Ferris was terrible but i actually didnt think she was that bad. SERIOUSLY the only person i had a problem with was "Hector Hammond". I hated him in the movie. My wife (who has no interest in comics but likes Batman Begins, The Dark Knight, Iron Man, Iron Man 2, and Captain America) hate the movie from the very beginning. She wanted to turn it off after only 4 minutes in to it.

You complain about not wanting to rehash the story, but then say they should lift from the story. Given the choice between seeing a faithful, bigger recreation of a story I like, or seeing a compressed, cobbled together Hollywood version of that same story, I'd rather just take a direct translation. Scene-for-scene remakes give us movies like Sin City, loose Hollywood adaptations give us Catwoman.

If the story isn't the same, what's the point of using the name and characters? They're the characters in name only if their story is different.

I think a better strategy would be to just assume the viewer knows the backstory, writing into the script little touches that reference previous occurrences in the comic. Origin stories drag things down, the reason the second movie in a trilogy tends to be the best is because they've already established all of the rules, and don't need to waste time on origins and can just focus on expanding on the universe and telling an interesting story with the setting.

Rather than re-write what's already happened in a different way, I would just carry on wherever it left off and tell a new story that didn't change anything already stated in the comic, but merely built onto it.

It was actually one of my favorite super hero movies I've seen. I'd like to see Sinestro as the villain of a sequel, though the Justice League movie will be first and he might be part of that. Who knows?