For anyone who visits my profile, Dead Space is genuinely amazing, go buy it now.
Play it on Hard difficulty, don't be a pussy. It adds a crap load to the game, because mutants aren't really scary when they can't two shot kill you.
For those of you who don't live under a rock (ye thats right, DON'T - people with lives don't know about games pfft), Dead Space is a knew thriller/horror TPS on Xbox 360 and PS3, it will make you jump like crap, and the dismemberment system makes killing stuff much more fun.