OK, I'll be the white guy that everyone hates.
I think black male/white female sex is the ultimate.
Black men are just plain more masculine, and therefore a more interesting pairing with the woman that sociological studies have shown is the most attractive female across all cultures: the blue eyed blonde. She's more rare than any other skin, hair, and eye combination.
My proof of the "masculine" statement? Larger cocks -- at least in porn, but I haven't seen any scholarly proof of this -- greater sperm count -- proven in academic studies -- and superior athleticism on most fronts.
This shouldn't make any of us white guys feel inferior in any way. It's just the facts. Proof? Get your woman drunk, eat her snatch, and just as she's really getting into it, ask her if she'd like to fuck a black guy. And don't be antimidated.
And for my ebony sisters: I've never been laid by a white woman like I have by a black woman who was paying attention. (My count: 43 white women; 7 black)
The perfect porn pairing for me would be white heads and black bodies on both participants. OK, maybe one amendment. White woman tits and pussy, black gal torso, ass, and legs.
OK, beat me up...