Any high-fantasy like Forgotten Realms, Greyhawk, etc. I like homebrew worlds because it gives a chance to explore a new world.
What are you looking for?:
I'm looking for a D&D 4th Edition game. I need a good story in order to really enjoy the game, so I like a game with an actual plot. I'm the type of player that usually writes a multi-page background for my character (with DM approval of course). I find that a lot of joking around undermines the storytelling, so I usually prefer groups that can take the game seriously, while still allowing room for humor.
I've played D&D 2nd edition, 3rd, 3.5, and now 4th. Currently playing with a group of friends about once every 2 weeks.