One of the most interesting bands (Megadriver) lets you download all of their songs on their official website, they play what they call Game Metal, covering many classic video game soundtrack (w00t! Sonic the Hedgehog!) along many others.

Cool thing is that the lead guitar player has two "different" guitars, one is made of a Genesis (or MegaDrive if you are outrside the US) and the other one has the format of Sonic's head (lol) truely amazing band

Hedgehog Metal:
http://www.megadriver.com.br/nobackup/ActionMetal/03%20-%20Stage%201%20-%20Hedgehog%20Metal%20(Sonic).mp3

Official website www.megadriver.com.br