Need good music site

I'm starting t pole more and have become bored with my music.  I've tried going to various free sites and they work for a minute and then something happens and I can't get music any more.  I was recently given a $20 music credit on emusic.com.  I checked it out and I can get 24 songs a month for $11.99.  Just wondering what everyone else does for music.  Is there a free site that works well that I'm not aware of?  Can anyone recommend a good paid site?  I know I can download from itunes, but I've heard there are other less expensive sites.  Any help would be greatly appreciated.