12. Half-Life 2 (PC, 2004; 360/PS3, 2007)
Platform: PC, 360/PS3
Frankly, HL2 could have very well have been our No. 1. But we wanted to see some new faces in then top ten. All the same, Gordon Freeman's return to Black Mesa was a cultural milestone as far as video games, not just shooters, went. 39 Game of the Year awards and several Game of the Decade nods stamped the title as a permanently revered game. The physics-defying gravity gun being one of the most memorable elements of Valve's baby. It allowed Valve developers to implement puzzle aspects into the shooter's action sequences (as well as bisect headcrab zombies with circular saw blades), adding yet another level of entertainment to an already nearly spotless series.