11. 'Doom' (1993)
Doom may seem tame compared to modern games. But when it was released in 1993, it singlehandedly popularized first-person shooters – and the blood and guts that go along with them. Although there were earlier games that helped shaped the FPS genre – Wolfenstein 3D chief among them – none did more than Doom to pave the way for today's violent shooters.