Did anyone heard about Dofus ? it's a tactical MMORPG.
The game is midway between heroic fantasy and cartoon and the humour an references to heroic fantasy themes make the game, I find, really funny to play.
Its easy to set up and it only has a small (30mb) download you can be playing in little time.with 11 unique classes and lush colourful cartoon backgrounds from a 2d isometric perspective...you might as well give it a go.
screenshots
here 