Karen O from the Yeah Yeah Yeahs gets points just for going from unattractive to performing on stage to becoming one of the most beautiful things I've ever laid eyes on.
Drew Barrymore and Salma Hayek also get many points for (at least maintaining the appearance of) being two of the nicest, most likable people in the world in spite of being absolutely gorgeous.
And you of course already know what they look like.
Monica Belluci (the Merylvingian's wife in the last 2 Matrix movies, the hooker in Shoot 'Em Up) has one of the sexiest voices and one of the sexiest bodies I've ever laid eyes on.
She has to be a little goofy, have a sarcastic/dry/highbrow/lowbrow sense of humor, value little over loyalty, and be at least as smart as me (though I'll deny that last part if you repeat it). And it wouldn't hurt her chances if she was short and had a big butt and short blonde or red hair.
Or be Persian.
Or Brazilian.
Or 1/2 Filipino.
Or Thai and Cambodian mix.