Portal.

this is game is one of the most brilliant games i have experienced and is good game to play after and while you rip some hits out of that nice bong you just bought. deffinatly recommened and makes your trip just that much better.

I played it through at least 3-4 times within the span of a week when I got it.

Also, if you liked the ending credits, the song was by Jonathan Coulton and he's got some other interesting stuff too. :p

I love Portal...one of the most brain wrenching interactive games ever...we brought the 360 up north to the cabin with us and played it whenever it rained...I love shooting the security cameras

It's about 35$ used for 360. I'm gonna cop that soon.