Since XI was my first MMO it may have spoiled me a bit...but SE was always good at their story telling. I never played SWTOR but ive heard good things on that end though.
If you love story, I'd highly reccommend playing swtor, at least from 1-55. Endgame is pretty abysmal in the game, but the actual leveling process is one of the best I've ever played in an mmo. The story is rich, the content is varied, and the progression is very well paced.