At around 53 minutes into the movie, there's a scene in Padmé's apartment where Anakin tells Padmé that he "feel[s] lost" and that the Jedi don't trust him. Then he says, "I'm not the Jedi I should be. I want more, and I know I shouldn't." As he says, "I know I shouldn't," he turns away, as if he can't bear to maintain eye contact with her while admitting this fault.
In the featurette titled "The Chosen One" on the bonus disc from one of my copies of Revenge of the Sith, there's even behind the scenes footage of George Lucas directing this scene, and he specifically tells Hayden Christensen, who plays Anakin, to turn away during that line.
