Actually, here in Ireland "cunt" seems to be applicable to everyone regardless of gender. "Nigger" isn't so common, but then there aren't many black people in Ireland.
I really fell in love with the word cunt in Australia. It's used there pretty frequently and without hate. As a word I think it is pretty close to perfect. The combination of letters is just so matter-of-fact, straight to the point and strong.
As they say, in Australia you call cunts "mate" and your mates "cunt". When it comes to these sorts of slurs my own usage is a bit different. I often call my friends gay, or nigger, or cunt, but I'm playing on the fact that using them is taboo, which serves as my justification. I mean, I met a black man once. I shook his hand, and didn't even flinch. Edit: I just remembered that sarcasm isn't apparent on the Internet...