Now I know that there are online services pushing to sell their online radio services.  However, if you are a big electronic music fan such as myself, you can't seem to find the variety of different genres on most of those services.

Here is a great site that has hundreds of electronic music feeds.  They are all free and you can do sub genre searches as well as specifying bandwidth, ect.  Of course, you do need winamp to play the feeds as the site is sponsored by winamp.  Fortunately, Winamp is free and one of my favorite music players on the pc.

http://www.shoutcast.com/ (for list of streaming stations)

http://www.winamp.com/ (winamp player needed to play streams)