SomaFM has a bunch of genres and is what I most often listen to. If you find a channel you'd like to hear, just click on it's picture!
My favorite playlists are:
cliqhop idm: Blips'n'beeps backed mostly w/beats. Intelligent Dance Music.
http://somafm.com/Groove Salad: A nicely chilled plate of ambient/downtempo beats and grooves.