I first downloaded Spotify about a year ago but barely used it ... now I listen to music on it EVERY single day. It's free ... maybe once every 10 songs I hear a 20 second advert for either radio, TV, music etc ... The music library they have is immense ... I'm finding everything I wanna hear including albums by artists I didn't expect ...
Everyone needs this. It's subscription based too if you wanna get rid of ads, allow downloading of tunes, and have mobile access etc... but even without subscription (which is how I use it), it's perfectly awesome.
www.spotify.com
Best of all the player/search system is very reminiscent of other players and is exceptionally neat and tidy, and quick. Also, each artist has info, and related artists. You get occassional tracks that aren't playable, but few and far between.
Good quality playback too