Vindictus is the best free MMO that's out there right now. It's not even a WoW clone at all. It's a beat'em up. And free. What more do you want? >_>

And you can customize the character to a degree. But yeah, other than Vindictus, Sean's nailed it on the head. WoW is really the best one there is, regardless of what people say.

..And regardless of the bad lore.