The Daily Grind: What does WoW do better than any other MMO?

We try very hard not to be partisan here at Massively. In our efforts to bring you the latest news and features for the entirety of the world of MMO gaming, we can't afford to show favoritism for one title over another; we love all of our virtual children equally! Having said that, then, we'd say that the majority of our writers have spent a good deal of time in World of Warcraft. Some still play, others have moved on -- some have moved on and come back.

This blogger in particular has spent no longer than a month's running time in WoW before quitting, only to return for another month after some time has passed; repeat recidivism ad nauseam. After researching and playing numerous other MMOs, and still not finding that one "home" game, WoW is always there, solid and reliable. But what is it exactly that draws one back after an absence? Or causes one to keep a running account there even when not actively playing? What does WoW do better than any other MMO?

(And if at all possible, please, let's keep this from turning into a reason to bash other MMOs, okay?)