What "virtual world" games are recommended?

I’ve been searching, and I can’t find a game that is good. I’ve tried “ROBLOX”, but there are too many immature people on there, can the people of Fluther please recommend good games for the PC that you can interact on? for example: Chat in/out side of servers, edit profiles, have respectable people or decent quality.
(preferably war or “just for fun” type games)