No. 98: Dead Space 2 – 100 Greatest Games Ever
No other games besides Dead Space can scare you so badly and make you shoot so frantically; and with enemies that encourage you to dismember them (they don't go down any other way), it certainly gives you more than your share of gore.
Dead Space 2 was improved from the original in every conceivable way, with more quiet, scary scenes, full control during the stunning zero-gravity sequences, and a vocal main character. Not enough praise gets heaped its lighting engine, which combines with stellar sound design to make you jump at every shadow.
Don't play this during the day -- you're better than that. Lights off, sound up... blankets nearby.