Ever since woxy went down, I've had a hard time finding a channel I like to listen to at work. But now I'm all up in turntable.fm. There are tons of different DJ "rooms" and the playlist is user generated. There are five DJs in a room, and if one leaves, you can jump up on stage. You can even create a new room if you want.
My favorite is when there are a ton of people dancing in a room. Don't know what I'm talking about? Check it out for yourself!