I have only played dead space 2, but I've heard that it's better than the first one anyway. I didn't think it was underrated I thought loads had heard of it and had played it making it a successful game franchise.
Awesome game though, I only played through it at night time, last thing I'd do before going to bed was play a few hours of dead space 2. Love all kind of gore in games and what's better than playing a guy who's going insane slightly?
Did you know Dead space 3 has been rumoured? Not sure when it'll be release but it should be pretty fricken awesome