2. Sinestro
DC ComicsA new movie could, in theory at least, kick off exactly where the last one left off. Without actually being a sequel of any kind, Sinestro could be the lead villain in a new Green Lantern offering, thanks largely to the fact that his evil origins will still be fresh in the memory after Mark Strong's performance in the first Green Lantern movie. Of course, those origins could still be touched upon and referred to - they're not exactly that complicated - but the movie could start with Sinestro wearing a yellow ring of fear and recruiting members of his own Corps to stand against his former allies. Essentially, even though he has already appeared, it would be a crime to not use Sinestro in any franchise involving the Green Lanterns, because he is their classic foe. It would be like Batman without the Joker, Superman without Lex Luthor or Spider-Man without the Green Goblin - unimaginable. Heck, in the event of a Blackest Night movie depiction in the future, Sinestro could even lend a hand to his former allies.