Multiple: Option's software, Game Melody Oratorio, includes lessons for songs Super Mario Bros., Sonic the Hedgehog, Tetris, Bubble Bobble, and The Legend of Zelda. Each melody has two modes, one for practicing the tune with visual cues, the other for playing the melody without any help once you've mastered it. Don't see your favorite video game song on the list? There's also a "Free Play" mode that allows you to experiment and play whatever you want.
[Via NEO Compo 2008]