Rules: Don't post Runescape... It's banned... So is Neopets...

Ferion: http://www.ferion.com/

pretty cool, like a real time space strategy game. make an empire, give it a flag, take planets, pwn n00bs, fun stuff... It takes a while to learn wtf your doing but in the end it's pretty awesome.

Bulfleet: http://www.bulfleet.com/

Basically the dumbed down, not as fun version of Ferion, but it takes less time to learn.

http://www.pardus.at

Kind of like VO in space. In 2D. Less twitchy.