Honestly? Individuals are attractive to me. I used to think there were women of whatever ethnicity that I would never go for, but then you meet a stunningly gorgeous woman from that ethnicity and you're just like "well... I guess I'm wrong." I've met all sorts of beautiful women from every ethnic background I can come up with. So at this point, I wouldn't claim that there is a race that attracts me the most.
Intelligence and a positive distance from the norm is probably the most attractive thing on a woman. Besides physical features, but those fade. It's pretty much a given that any woman can get the blood flowing to my genitals, but getting the blood flowing to my brain is much rarer and I'm proud to only cultivate relationships with beautiful and intelligent women.
I will say this, however: Latin culture tends to produce very attractive women. Love dancing, drinking, and they're passionate about speaking their mind? Hell yes.