I like WoW because there's always something to do, even when you have no one else available to help you out, I always felt a sort of dependency after watching my friend play Guild Wars, I'm probably wrong though, so that's just me.
Aside from the 8 year old e-penis farmers EVERY game will have, if you check out the realm forums on the WoW site, people are pretty cool (for the most part, excluding e-penis farmers). I've been wanting to join an RP server kind of, I can really see how it's fun..then again, I don't want be in the deeprun tram walking up on two night elves cybering while a dwarf is stroking his hand cannon..