I do the usual suspects:
Soma:
http://www.soma.fm/ (yay, it's back!)
Digitally Imported:
http://www.di.fm/
DIU:
http://www.detroitindustrial.org/
DIU seems to be experiencing difficulties for the past 6 months, and their selection was a bit limited, but it was always a nice break.
That, and my own private streamer! I stuck all my mp3s into a db, wrote a loader module for Icecast (
http://www.icecast.org/), banged out a PHP front end to control and see playlist, etc. It's better than a file share to my work machine, which is what I was doing before.