Superman is a LVL 60 Human Paladin

Alright, he hasn't really said what his character's like, but Brandon Routh has admitted that he playes World of Warcraft. "I just like that world. I love medieval time and swords and horses and that kind of thing. It's fun to live that out, and I can play with some friends who also enjoy the game. It's challenging and mentally engaging. It's just fun." There you have it, even superheroes game.

[Source]