this is a virtual gold mine of old school synthy sounding music. Its mostly released under creative commons licenses allowing you to listen/distribute it for free as long as the artist is credited.

[url=http://www.8bitpeoples.com/discography_gfx.php]8bitpeoples discography[/url]

Their mission:

The 8bitpeoples first came together in 1999 as a collective of artists sharing a common love for classic videogames and an approach to music which reflected this obsession. Our primary interests were to provide quality music for free and most importantly to have fun. In the years since, we have grown in rank and expanded our goals.
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i've only just started listening to it but here are a few of my favs so far:

8bp075-01-kplecraft-okesuchi.mp3
8bp067-05-coleco_music-honey_we_are_chatting.mp3
8bp066-02-vim-hazel_dave_aaron_and_the_tall_one.mp3
8bp064-04-handheld-6-in-1.mp3