I'm not really sure if this is the right forum for this, but it might interest some of the people here.
For the few past months me and Datschge from Snesmusic
have been working on a site that will host music from all handheld systems, starting with B/W Game Boy and going chronologically through all games released up to... well, whatever system will be supported by then (currently the newest one is PSP).
It's been in a public beta for a few weeks, so there is quite a bit of music to choose from, with ~4 new soundtracks released daily.
If you feel like giving good old Game Boy bleeps and blops a try or maybe can contribute any of the missing rips (both Game Boy and Game Gear music ripping is a bit beyond my puny hacking skills), you can follow the link above. More information available on the actual site.