If you've missed out on some of the great co-op titles of this generation on the Xbox 360, now's your chance to pick a trio up for around $40. Amazon is running a promotion that includes 36 titles, 9 of which are co-op games, at a buy 2 get 1 free price. Most titles are $20 a piece.
It might be a good time to snag Resident Evil 5 with the upcoming DLC coming out, you'd be able to own the Gold Edition for a fraction of the cost.
Source: Amazon.com