Depends. I for one am disgusted by characters that have a pale, make-up like face, ridiculously elaborate hair and skimpy clothing. I always build my female characters with vanilla resources, and aim for a natural, tough chick style that would fit for some stranger who has massacred hundreds upon hundreds of people without a blink.
http://fallout3nexus.com/imageshare/images/1079527-1277836341.jpg is my main female character. Claudia Hunter, who also was my second (although longest played) character in Fallout 3.
EDIT: And since sixiness these days also applies for men, see my avatar for my main male character Troy Hunter. Well, he isn't my main male character in NV but the one who is is Colonel Autumn so...
http://fallout3nexus.com/imageshare/images/1079527-1272446846.jpg
http://fallout3nexus.com/imageshare/images/1079527-1272446975.jpg
I do have another female character but I'm too lazy to start the game for one picture.