If you didn't know it there's some cool software for making loop based music called Acid. It's pretty cool and very easy to make something interesting though of course much harder to make something good. And, there's a free version you can download if you want to try it out.

Anyway, if you go to this site they have loops and samples from several famous or semi-famous artists including for example The Beastie Boys and Depeche Mode. It's kind of cool to mix your own versions of their songs especially with all the parts separated out. Drums, Keyboards, Voices etc all separate.