The Dunmer because of the Lore behind them and because they really fit my playstyle as far as what they're naturally talented at.
I'm also really interested in the Redguards. While not my favorite, I might create a character that is a Redguard.
As far as which races I don't like, the Bosmer I found short, fat, and really annoying in OB so I don't like them much. Imperials aren't at the top of my list either although they do have my favorite province so far.
Also near the top of my list are the Nords. They are rugged and look a lot like me. Blonde hair, blue eyes. I always thought I'd role one but just am not drawn toward using a sword and board.
The beast races are also pretty cool. Really the only other character I've played and had fun with has been a Khajiit Vampire in OB. I really loved it and am looking forward to trying one out in SK. I've never played an Argonian because they just seem really dirty by the name of their homeland and the stories I've heard about Black Marsh back my assumption up.
And lastly, I'm neutral on the Orismer. I've never had too much of a problem with them and have never been treated too badly by one. Same with the Altmer minus the way they treat everyone. They are a-holes but I'm really drawn to their background and Summerset Isles. That land sounds awesome and I can only hope that we get to experience that province one day.
EDIT: Sorry for making this into a like/DISLIKE race post. Hope you'll forgive me

Favorite Weapon: Bound Sword or a combination of any destruction spell.
Favorite Armor: Ebonyflesh with the Arch-Mages robes.