If we're going for badass, I'd say Norse mythology. But any mythology has too many drawbacks, I don't want the gods getting pissed at me for screwing a woman or whatever. Edit- that was a bad example, that probably pertains more to other religions than mythology, if at all. But I hope you get my point. The gods know payback. I'm not sure I'd make any religion real. I'm happy without worrying about going to hell, but having the philosophies hold a family together (my family is Christian, I'm somewhere between agnostic and atheist myself).