It's actually common to include black-haired under the term brunette, especially with that brunette/red/blonde-question, which makes this whole deal a bit pointless.
If I think about ex-girlfriends and other girls that I've had something similar on with, the amount of blondes is way too damn high. Almost all of the one-night stands or lesser sexual encounters have involved brunettes almost exclusively, so whaddaya know. And many of the girlfriends dyed their hair so it sometimes changed from category to another.
Still, generally I'd say blondes. But also redheads, some are incredible. And beautiful brunettes... I love women, is that not enough?
edit: Merriam-Webster to support my first statement
Definition of BRUNET
: a person having brown or black hair and often a relatively dark complexion ?spelled brunet when used of a boy or man and usually brunette when used of a girl or woman
