Probably the obvious choice, Batman Begins. I watched the Nolan Bataman films before the Burton ones, I thought Nolan's were superior, but that's just me.
Second favorite'd be the Iron Man films, I was never a huge fan of Iron man in the comics, but the films were great, though it's probably largely due to Robert Downey Jr, he's the type of actor I could watch read a phone book for two hours and still be entertained.
Thirdly would be either the Spider-Man series (Yes, even the third one, ESPECIALLY the third one.) or the first two Superman films, simply because of the main characters.