I love Audiosurf. It's probably one of the best games ever. You can play it on and on without getting tired of it.

    Audiosurf is a next-generation (in gameplay, not performance requirements) high-speed racing action puzzle game which allows you to play as one of over ten characters with differing difficulty and game style as you race down a track synchronized to your music, in pretty much any format you have, save MID and XM files. I'd recommend it for anyone with ten dollars and time to kill. Plenty of time to kill. You will need it. Its graphics, on minimum settings, are superb, it has online (though breakable) scoreboards, and it is an truly enjoyable experience.

    I had a longer rant written, but JoeUser went boom, and I lost it. You really only need one paragraph anyways.