When word of the Cataclysm races came out, I admit I was excited about the worgen. I had once played a werewolf character in a game of D&D, and it amused me at the idea I could recreate her in some aspect within WoW. Then the dances were released. At first I was undeterred; I play my gender, so the male dance didn't bother me much. However, things changed when the female dance was finally released on the internet. I was quite displeased at the choice for the female's dance. It was too much; I decided then and there that I wouldn't roll a worgen, purely because of the dance.
I know it sounds petty, but the racial dances are a bit of a deal-breaker for me. When I was first introduced to WoW by my cousin and friends, I looked up the racial dances to see which ones I liked best. Having only a trial account, I went with tauren as my first choice, as all my friends played Horde, and I thought the Electric Slide wasn't a bad dance, trolls being a close second.
What about you? What sort of thing about a race or faction breaks the deal, causing you not to choose them?