Tie between Khajiit and Argonian. Voted Khajiit because Argonians will probably get enough votes from this board anyway. As for why, Argonians because of their relation with the Hist and Khajiit because, just read Ahzirr Traajijazeeri. And the many forms of Khajiit are fascinating and I hope we get to see them in future games.
The mind is like a parachute: it only works when it's open