Dead Space 2 is more action-y while still retaining horror elements. Dead Space 1 is scarier and closer to a true survival horror game. Depends what style you are looking for.
I'd also recommend X-COM to everyone. I wasn't really into strategy games, but I loved X-COM.
Also 2nd Bakan's recommendations of Dishonored, Deus Ex, and Dragon Age: Origins. 3 of my favorite games from this gen.