Many autistics have trouble putting what they feel into words: Not Dan Bull. He puts it into words, sets it to music and raps it. [more inside]
VGMix is a site that hosts MP3s made by video game afficionados who have remixed the tunes from their favorite video games, old and new alike. Check out the releases page and try out a few songs. You can also search for songs by a particular game system, genre, specific game, etc. (Unfortunately, search seems broken for me right now, but it usually works!) The users generally provide extensive reviews that will help you sort out the great from the mediocre before downloading.
Overclocked Remix is the home of some fantastic game music remixes in a variety of styles - from relaxing piano to higher tempo hybrid affairs. Have a rummage and a listen..