Just gonna disagree a bit there. The problem wasn't Hayden Christensen, but the direction. As the Nostalgia Critic pointed out, when he doesn't have to talk, he does quite a lot with just the facial expressions. The whole prequel trilogy is a classic case of good actors being stuck with a bad director.
I know I'm nitpicking, but I'm tired of people picking on him for something that was out of his control.