I've been playing more Beat Hazard. While Audiosurf is quite firmly a rhythm game and sets out to create very literal interpretations of the songs you feed in, Beat Hazard is more about the broad strokes. It's an arena shooter first and foremost with the bonus of action following the soundtrack you choose. 's a nice way to experience songs.
$7.49 on Steam. I still wish there were per-song leaderboards.