On Weds, my students told me about Pandora Radio. It's a web site that serves as your own personal radio. You type in an artist or a song and they'll develop a playlist of music similar to the song/artist you like. You can further refine it by giving particular songs Thumbs Up or Thumbs Down.
The nice thing is that it introduces you to new music and musicians similar to the ones you like already.
It does not suck, which is one the highest compliments we give in the south. (Like when I saw Andy Garcia on my morning jogs in Toluca Lake and thought "That man is NOT ugly.")
Let me know what you think.