I'll try to put the songs with interesting interpretatoins on Audiosurf. So far:

Sadness - Gspott

Until you love me - 4trings

Sadness especially gets ridiculous on ninja mono. 

you have to try this one out, seriously!

Nine Inch Nails - The Great Destroyer

Nightwish - Wishmaster
Metallica - ...And Justice For All

These two are easily my favorites so far. They have an awesome mix off speed and bass that makes any song really exciting, with lot's of speed fluctuations.

Electric Light Orchestra music...it totally fits the trippy feel of Audiosurf.

And Brawl music haha.

19-2000 [soul child remix] - Gorillaz

I played to Daft Punk's set from Coachella 2006 and it was heavenly.

DJ Shadow - Blood on the Motorway, and Tool - The Grudge are the two best I've played so far, just the perfect mix of calm and absolute intensity, especially The Grudge :D

Also from what I've heard, Nine Inch Nails - March Of The Pigs makes for an insane ride!

:D

Audiosurf is awesome!

My favourite tune so far is Breaking the Law by Judas Priest (also my favourite tune for breaking the law to).

Helter Skelter and Tomorrow Never Knows by The Beatles are pretty cool too.

You want a REALLY hard song??

Try this song, it has no sound at all...but it's probably the hardest song in existence:
http://www.megaupload.com/?d=HPN5W2XB

Somebody must have put tiny, tiny, TINY grooves into an mp3, making the ride INSANE haha.

I love to play the songs from Mono (japanese band) and oceansize with audiosurf this is becouse they have o lot of changes in there songs. with mono you will mostly beginning going up, but all of a sudden drop very hard, with oceansize it's going up and down.