Batman. Millionaire playboy that goes out at night and fights crime, sounds good. I don't want to pick Superman because being invincible doesn't sound all that fun to me.
I wouldn't want to be Superman, because... This Reason I would be Batman, because he has money and the technology. To me, that's pretty sweet. Plus, he looks cool. :P
I've always been a big batman fan just because he seems more real than others. He's a hero not a superhero. I'd like the idea of a batman like character on a middle class budget.