If I had to pick one thing, hmm. Anakin's "turn" to the dark side was crap and has anyways bothered me. I know He'd been "turning" for quiet some time but come on. He just snaps and kills everyone? That was the worst possible way lucas could have had him turn. "On no, I did wrong, so I'll just sell myself to you and go kill everyone including kids." I mean WTF. I suppose it was a fitting turn for the whiny little **** that he is, but still it was annoying. Also, well we're on the scene, I think having Anakin kill Mace Windu like that was crap, the emperor should have killed him in a hard fought battle, not was was essentially a cheap shot. I can think of more things but I'll leave it at that.