Amazon's Gold Box Deal of the Day today is for the recently released Portal 2. Your price? $34.99. The title features a two player co-op campaign as well as a highly entertaining single player story. You can read our review here.
Sadly only the 360 and PC versions are on sale for this price, the PS3 version is apparently sold out so there is no sale to be had. It seems a lot of folks wanted to take advantage of the free PC copy in the PS3 version of the game - a smart move no doubt - except when they found out they couldn't redeem it quite yet.