Left 4 Dead 2

Category : 1st Person Shooting
Rating : 90% (by gamespot.com)

Recommended System Requirement :
-OS : Windows 7 / Vista / XP
-CPU : Intel Core 2 Duo 2.6 GHz or better
-RAM : 1GB for Windows XP / 2GB for Windows Vista
-VGA : ATI X1600/nVidia 7600 or better
-HDD : 7.5 GB of free space

Screenshots from my PC:

(Click pics to enlarge)