Vader's scream at the end (MAY CONTAIN SPOILERS)
Most of the criticisms of the STAR WARS prequels I agree with, however there's one complaint many have that's actually always bothered me. At the end, when Darth Vader has just been placed in his black suit, and Palpatine tells him his wife and child (neither of them know he had twins) both died in childbirth. Vader then screams,"NOOOO!!!!" And people are upset by this, calling him a whiny pansy? Why? Padme was the woman Vader loved. He had been looking forward to becoming a father. Then he's told his wife and child, now the only family he had left, are gone. How did you guys want him to react? Even after turning to the dark side, he was never supposed to be completely unfeeling, but more complex.
This also brings to mind the scene in ATTACK OF THE CLONES when Anakin (before he becomes Vader) returns to Padme after killing the sand people and has an emotional breakdown. Again it's always kind of irked me that people have a problem with this: Anakin finally returns to his mother after years of separation, only to see her die almost immediately after they meet again. Did you think he should've just shrugged it off like it was nothing to him?