Come to think of it, Michael Sheen also seemed to be the only one having fun in TRON: Legacy, as well. Don't get me wrong, I liked TRON, it's just he was the one guy to really make his character stand out. I mean, think about it, name the characters in the movies. Well, there's Jeff Bridges, digital Jeff Bridges, son of Jeff Bridges, 13's skintight outfit, and that guy who ran the club; he was pretty cool.
That's when you know you have a wicked talented actor, when he can alter your overall impression of a movie just by being in it for ten minutes. See also: Jack Nicholson getting an Oscar for nomination being in the first and last scene of A Few Good Men.