Kohina (http://www.kohina.com) Is a great retro computer game music radio with ogg stream.

It's mainly C64/Arcade but it has also Amiga,PC,Atari XL,Spectrum etc tunes.

The music is entirely recorded from original hardware so there is no emulated music.

Nectarine is also good...

http://scenestream.net/demovibes (http://scenestream.net/demovibes)