The story is the main draw, and worth experiencing IMO, even if it takes forever to get going, but it's still a good MMO. I don't know if I'd call it "the best of all time," but I've enjoyed my time with it. The reason I keep my sub between story patches is because I like hanging out with friends and being in the world, which is what an MMO is all about.
I don't really have the time or interest for the super challenging content it offers, but I level jobs, I do treasure hunts with friends, I do Deep Dungeon, I obtain cool outfits, and I hang out at a friend's RP bar.
Like any game, though, it's not for everyone. If you like tab-target MMOs, WoW has better combat I think.