As a result of the basic edge-detect AA method, Dead Space 2 suffers quite badly from jagged edges and pixel creep. These problems aren’t all that obvious while on the move but if you stand still you’ll definately see that most straight edges in the game are jagged. The issue is of course exacerbated by the fact that you spend most of the game in boxy corridors with lots of straight lines. Unfortunately it’s not possible to change the method of AA the game uses via the in-game menus. In fact the only AA option available is a simple on/off toggle in the Visuals menu. As a result you’ll need to get down and dirty in your graphics driver if you want the game to look its best.
To get around this you’ll need to download a small program called Nvidia Inspector which allows you to adjust the AA flags that your driver associates with a given game or application. You’ll also have to turn the in-game Shadow Quality setting down to Normal, as the game refuses to render any shadows at all with this option set any higher while MSAA is running.
Once you’ve downloaded and open Nvidia inspector, next to the driver version tab, there's a little icon with the screwdriver and a wrench, click on it, find the Dead Space 2 profile from the drop-down menu in the top left of the window. This should show all the driver-based settings applicable to the game. Now click on the setting value entry next to the Antialiasing Compatibility field and change the entered value to 0x004030C0.
Once this is done you can scroll down to the Antialiasing - Mode and Antialiasing - Setting options and set them to 'Override Application Settings' and 4x respectively I also selected NONE for Antialiasing - Behavior Flags. You can of course set a higher AA setting if you wish, and you may also want to look at some of the other options listed here such as the texture filtering and ambient occlusion (a fancy shadow technique) settings.
How to Enable AA in Dead Space 2
NVIDIA Forums