Manga? I think Guts is the best manga character ever. Ichigo is close to second.
Standard American comic book heroes? I like Batman a lot, especially Frank Miller's Batman. Mark Grayson is good too, although I'm late to Invincible.
I like characters that have moral dilemmas. It's a sensationalization of everyday issues where you have to decide what kind of person you are going to be.
Super heroes reflect the moral core of the culture that produces them, but then so does all fiction. Maybe not broadly, but I think the more popular they become the more they reflect the society at large.