hmmm...my preference would be
vampire, elf, human, or halfling....
in that order....
as for other races I've enjoyed playing....
Thri-kreen
mongrelman (that character eventually became a human female with 18 Chr thanks to the Deck of many things...it was odd role playing that first month...that first cycle)
humanoid bat (stats as a halfling, but gimped a bit for a glide ability) for a planescape game
ghoul
cambion/half-fiend (satyr/succubus)
There are a couple of races that I always think I will enjoy but don't....and those are half-dragons and dwarves. I like them...but I think I should just play them in one shots.
I really can't say that races are the defining trait for my characters. In general I think the genders I play are more defining. My males characters are usually family oriented polygamous, and hetero. My females are usually monogamous lesbians. Really the only exceptions are just games that didn't continue long enough to bring out relationships (i.e. 1 or 2 shot games)