This is a really hard one for me. I am debating Bosmer Dunmer Khajiit and Argonian. It depends on the playstyle, I guess. Bosmer. That is what I choose because I love archery, then Argonian because of their waterbreathing, as it allows me to search shipwrecks, then Dunmer due to their resistance to fire and how they start of with multiple spells. Then Khajiit because I love brawls and they give me an advantage, plus they let me see in the dark parts of caves quite easily, although so do vampires. My least favorite has got to be the nord or maybe redguard. Nords are only good against ice wraiths and frost atronachs really, and I have never had any use for their battlecry ability. Redguards are better, but mainly because I love their survivability, though argonians are good at that too. I guess I don't really like bretons either, though that is because they are only really good at fighting magicians and are not as great at becoming one.