Wired did an article on bands who cover only soundtracks from Nintendo Entertainment System (NES) games: Minibosses vs. NESkimos
Although the Minibosses come through with almost prog-like rendition of MegaMan 2, I have to give it to the NESkimos for their Double-Nickles Minutement-era rendition of "Mario" (although I subtract a point for using the totally bullshit CafePress for merch)
Both bands are insane for learning this stuff.