Loved playing Dead Space on my PS3. It's one of the now rare breed of games that focus on telling an engaging and decently sized story(around 12-16 hours). I was always on the edge of my sofa waiting to see what happens next and terrified of what lurks around the next corner. Surprisingly, the game is most scary when nothing happens, only the sense of atmosphere and anticipation, that's how thick is the atmosphere the graphics and sound create.
The gameplay is super fun and makes you stray away from the convention headshot mechanic and makes you be creative by having to dismember the monsters you encounter. The weapons are also very creative (regular space mining tools) and are upgradable in a RPG fashion by finding or buying power nodes. This encourages replay and exploration to find items to trade for power nodes.
The game also runs flawlessly on the PS3 Slim, always with 30FPS and no screen tear. It also requires a minimal install, just a few megabytes.