Where to sample music

Any good websites with a large selection of music where you can sample the whole song? Obviously playback quality doesn't matter. I know of a few, but most of the music is mainstream and/or you only get to hear the first 30 seconds.

Don't overlook local CD vendors such as Borders which generally have numerous listening stations whereyou can sample numerous CD's- the entire CD if you wish. Overpriced, but no obligation to buy.
Pandora is awesome. I've been listening to it all day.

I also find great stuff at CDBaby.com. They don't let you listen to the entire song but they do give you very long cuts.

CD Universe.com has samples to hear but not the entire song.It is very good at prompt delivery.