If you want really obscure stuff, it’s out there but you’ll probably have to look further than even video games. If you prefer ambient/electronic music with few or no words, a lot of artists have cropped up in this genre thanks to the bit-torrents, filepilez and gnutellas of the world. Electronic music took advantage of (arguably created!) this distribution mechanism as the genre’s relatively niche´ sound has proven to be difficult to effectively promote outside of its small fan base.
Just because things like iTunes exist, doesn’t mean you’re still getting access to obscure, different or incredibly “indie” music. Like anything else, for the real gems, you’ve gotta dig deeper.
If you’re up for some digging, here’s some I’ve discovered and liked: Mylo, Kavinsky, Digitalism, 65daysofstatic, Four Tet, Explosions in the Sky, Boards of Canada, oh and how could I forget: Aphex Twin.