Know of any great bands/musicians that you think need more exposure? Help spread the word and help out some forum members here with any good music recommendations that you can offer. Also, the term "unknown" is subjective, so please refrain from any "LOL I know those guys n00b!!!1111one" crap. Pretty much anything thats not played on corporate radio/MTV etc works.
Nuclear Rabbit - It's a damn shame these guys aren't mainstream. They kind of have a Primus feel, but are kinda tough to pigeonhole into a specific genre besides "Metal". Jean Baudin is the best bassist I've ever heard - Check out this vid and see if you agree:
The Disco Biscuits - One of my favorite hippy jam bands with a touch of electronic and spacey undertones. Don't bother with their studio work, just try to get some of their live shows. I've seen them live two times and was very impressed.
Edgey - Great Drum and Bass DJ. Does some crazy BPM speed and has very intense and experimental songs. He was pretty big on mp3.com back in the day I think.