If you eventually intend on raiding, Draenei blow all the others out of the water if you're min-maxing (hit rating aura + more mana). For PvP, dwarves are the best with Stoneform. For casual play or instance healing, human are best due to increased spirit and the rep bonus. Night elves are good in PvP (shadowmeld) and have a little extra damage.
In the end, it comes down to whether you want to min-max at whatever you intend on doing, or what you can put up with looking at for the next 70 levels.