Mark of the Ninja, a stealth game I've had my eye on for quite a while just went on sale on Steam for 75% off, making it just $3.75. Consider this one purchased.
While reading up about the game while the payment was processing, I found out that summer 2013 will bring a Special Edition DLC for Mark of the Ninja to all those fans who were clamouring for more. Depending on the price and reviews, I'll probably snag that too when it comes out.
It's hard not to get excited about a game that IGN says is "the benchmark by which all stealth games are now measured."