Iron Man.
The Dark Knight takes itself really seriously also, which to me, makes some of its themes look sillier. It's supposed to come across as a more plausible kind of Batman, but Iron Man managed to be really sincere and do a better job of still knowing that it's ultimately comic book fair. And Batman was just not as interesting a character this time around. Joker was interesting but I still couldn't quite buy it.
Yeah, Iron Man was brilliant. It has that hyperactive pacing that's all over Hollywood in recent years, but they packed it with meat and potatoes and it was still just plain fun at the same time.