What do you think of Phantasy Star Online 2 as a "virtual world"? By virtual world I mean a persistent universe as in several MMOs, and programs such as Second Life and IMVU?
I think it's a decent virtual world, with a lot of avenues for character customization and socialization. I do think the world could be expanded on and given more locations to explore, though. Some other MMOs have gigantic worlds to explore. Same thing with Second Life and IMVU (although the latter consists of disconnected worlds.)