About a month ago I finished 15 tracks of music inspired by the game
Portal. The music is all very ambient and dark toned. There are more filled-out tracks with swelling synth pads and sweeps than there are quiet minimal tracks (i.e, more music than ambient noise).
Lots of bass! For all you bass enthusiasts. Some of the tracks are faster-paced with drums too, though sparse rhythms. There's some glitch / IDM stuff going on in there too.
It's good music to chill out with if you have a nice pair of headphones or a good sub-woofer.
Here's a direct download:
THA - Portal Music.RAR And here's a download page with the individual mp3 files for download:
PORTAL INSPIRED MUSIC Peas,
- Hamst3r
PS: I suggest listening to the music in the order shown on the download page. 
