I have to say brunette, because I lean towards dark hair, but if I had it my way it would be extremely dark hair, very dark brown or of course, black.
The hair maketh the man...is something no one has said and no one agrees with.
I like dark because it works with the other thing I like - pale skin. It's difficult to make blond hair look good with pale skin, unless it is silvery blond or fair hair. But yeah, dark hair rocks, and so do brunettes. :)