These guys are, for lack of a better word, awesome. Their emotes are fantastic. They sell an evil penguin pet and a cool fishing item (the Mastercraft Kalu'ak Fishing Pole) that probably won't be replaced for the duration of the expansion. Their ships are giant turtles traveling along beautiful coastline with a vendor on board (seriously, riding these at night = an endless series of Kodak moments). They get my vote as the faction that immerses you most thoroughly in what they need and what they're doing to survive in an increasingly hostile Azeroth, and I'm wondering if, given Northrend's various difficulties, they might be convinced to seek warmer climes just so we don't have to give them up.
Agonizing rep grinds have plagued the game since classic, but the Tuskarr are such a well-realized bunch that even at exalted I love hanging around their villages. What's your favorite faction, and is there anything about them you'd like to see repeated with future reputation grinds?