Back in the day, I was using launch.com than I stop. There is a new guy at the office that started and he's currently using launch.com to listen to music.
So today I started again. I found that they have really kool features. You create you own online radio. Select the kind of music you want to listen to, the artist and you can rate them. So if you rate them low, you won't hear that song again. But if you rate them high, you will hear it more often.
They have a huge database of Artist and Album an Song.
Have a look :
http://www.launch.com