I think Matt Bomer (White Collar on the USA Network) would be the perfect choice for Batman/Bruce Wayne. Not only is he a great actor, especially when it comes to playing the suit and tie badass characters, but he literally looks like Bruce Wayne. He has the dark hair, the light blue eyes, the strong jawline, etc. Not only that but he looks similar to Henry Cavill since both Bruce Wayne and Clark Kent look very much alike. There is a rumor he was up for the role of Superman but got shafted due to a personal reason.
