I almost always play human characters. I think my first AD&D character was a half-elf, and I once played a Chaond (chaos planetouched), but usually my PCs are “plain” humans. I don’t know why exactly, but maybe it’s because I don’t like the archetypes associated with the standard demi-human races. In my mind, all dwarves fight with axes or hammers, and wear horned helmets. All elves use bows, and all halflings smoke pipes. Stereotypes, instead of archetypes.
Or maybe I’m just not attracted to the archetypes these races represent: if I wanted to play an archer, maybe I would play an elf. But playing an elven archer doesn’t appeal to me: I usually play witches or thieves, both of which are human archetypes.