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.