Worgen for me. A really badass awesome race completely shafted it seems. No lore for worgen players past level 12. And if you wanna see the rest of your lore roll horde and play silverpine.. which is also happens to be the best questing zone in Cataclysm. They has such promise aaaand they fucked it up. Draenei are a close second, huge potential rich history, no limelight.
Best races lorewise are the forsaken, orcs, humans and tauren in my opinion.