In Episode I at around the 1 hour 33 minute mark where the Queen decides to go back to Naboo right at the end of the scene Palpatine gives a little smirk just before the optical wipe moves upwards. It is (as far as I know) the only genuine piece of subtlety in the Prequels.
Of course, it's completely ruined when the audience is slapped across the chops with the big close-up of him at the end of the movie. But that little moment... I like!