Seen any...
elves? Bwah ha!
My favorite race is Khajiit. I don't think I've ever met one I didn't like, even the ones who are trying to rob or kill me.

I used to really like Bretons until I started shopping at Belethor's on a regular basis.

Actually I don't have a least favorite race. There always seem to be a mix of good and bad (and horribly annoying) people in each race.