Dead Space: Extraction
Being a prequel, the ending of Extraction pretty much ruined itself. And the way it answers each question about the Dead Space story with two more questions is a bit perturbing. Outside of that, I'm really impressed with this package. It's got a compelling and exciting campaign (at least, it was compelling with two players), as well as a story-less Challenge Mode where you can just blow necromorphs to bits for fun.
It also has, in the form of bonus features, a "moving comics" presentation of the Dead Space comic books. Me and my comrade-in-space-arms watched these after the campaign expecting some trite fanservice shit, but they're actually quite good, largely due to some excellent voice acting and thrill-a-minute pacing. Apparently you can also watch them on GameTrailers if you're so inclined. There are a lot of worse ways to spend an hour or so.
Progress: Finished on Hard