Exdeath definitely does it for me. Not really for any good reason, but:

He reminds me of garland from FF1, but his story is slightly better or more advanced (Or more the same?!)

He's determined to get what he wants, he succeeds with blunt forwardness in his actions, and he is the only villain who actually aknowledges his horrible horrible mistake in driving so evilly for power when the Void overcomes him. He's the only villain I've ever felt at all sorry for, because he thought that he was right, but it was actually the corrupting force of the wrld that was controlling and corrupting and ultimately destroying him.

Tragic.

(SPOILER)Yet not too tragic because he was a punk to the Warriors of the Dawn in the past, and deserved to die rather than be locked in a prison that was one day bound to fall apart and let him loose.