By far the best results you will find for MP3s will be on the Kazaa network right now. However Kazaa has problems with spyware where ads pop up all over the place and advertising companies monitor your habits to target you better with the software. But a group of people have taken Kazaa and stripped it of the spyware and it runs a lot faster. It's called Kazaa Lite and you can get it at
http://www.kazaalite.com/. Just make sure if you update it after you download it, you get the update from their site and not from Kazaa.com.
-Rudey
--Oh and download "Do the Urkel"!