In life, the simplest questions are usually the hardest to answer. Once I think I knew for sure white I love white women... But I can't anymore. And I hate comparing white women over black women. In the end, they're both women. I'd say the same for Asian women, except I'm yet to meet any Asian woman to know.
I guess its more fairer to say that I'm attracted towards white women, not just for sex, but a lot more I can't describe. They're sexy and open-minded a lot about stuff like sex & sensuality. Maybe in time I'll get married to one... Or maybe not. My fingers are crossed.
As Dsoul said, it's difficult to put into words. Personally speaking, I'm attracted to women in general; I'm not sure how much race factors into it. From a sexual stand point, the white women I've been intimate with seem more inclined with their sexuality. Many of them were more open-minded , and seemed to genuinely enjoy certain things. However, I can't say that's a trait that only white women have.
@IL: I like the way you put it down. Never a good thing for one to look at such things with race or colour on the mind. If only people would just fall in love and stop wondering what colour of a person's skin he/she is, the world would be a much better place to live in. Better here than on Mars.