This is a listing of music that was (partially) made with linux and is really well recorded IMHO.
Wether you like the style of music is a totally different question of course :-)
Hope you enjoy it !
Jazzy-electro by Attack
http://sharpattack.bandcamp.com/
Electro-ambient by Pneuman (some nice Air influences)
http://pneuman.bandcamp.com/
Avant-garde rock by Platypuse Egg
http://platypusegg.bandcamp.com/album/little-street-of-happiness-2
Experimental-electro by Chordpunch
http://soundcloud.com/chordpunch
Crazy stuff by Sebkha-Chott
https://soundcloud.com/Sebkha-Chott
Metal by Pupkovem (drums are Hydrogen)
http://soundcloud.com/pupkovem/cutthroat_notalive_instrumenta
If you know of any other album/demo that was recorded using Linux be sure to let me know in the comments below!