Orginization XIII
as others have said, though they simply wanted to exist, their methods could deffinietly (sp?) be considered evil. the ends do not justify the means. also, i remember somewhere (cant remember where exactly, unfortenetly) that Xemnas also plotted to become a sort of god like being (i may be wrong...). and remember, they cant feel sorry for their actions. Xemnas states right before you fight him "very good, you dont miss a thing. i cannot feel sorrow. no matter what misery befalls the worlds. no matter what you think. what you feel. or how you exist!"
Maleficent and Pete were, of course, also evil. however, they sort of took a backseat to the Orginization (compared to KH1 in any case). and we must remember that they did end up saving Sora and Co (perhaps even getting killed for it, but there is no proof as of yet) right before you encounter Xemnas.
as for Sora and Co., i seriously doubt it. true, Sora did kill people that simply wanted to exist, but remeber just how they attempted to acomplish this goal. Sora simply was commiting the lesser of two evils.
which do you think is worse, Killing a few guys in order to stop them from (effectivly) killing countless people, or do nothing and later feel guilty as countless people (maybe even friends) die, knowing that you could very well have stopped it from happening? this is, i believe, an example of what is called Hero Syndrom (sp?)
with all due respect,
Merlin326