Doom

Hot on the heels of Wolfenstein 3D was id Software's 1993 sci-fi horror shooter, and arguably one of the best known video games ever, Doom. Releasing only a year after Wolfenstein 3D, the system requirements took a huge leap forward requiring a 386 processor and eight times the RAM required for its predecessor, a whopping 4MB. Legendary developer John Carmack -now working on making viable VR technology with Oculus - created the idTech 1 engine the game uses, otherwise known as Doom engine.
Despite the fact that almost every enemy in the game is a literal demon from hell, interest groups rallied together against the ultra violence inherent in the genre and so began the frequently-debunked myth that violent games lead to violent behavior. In fact, these groups even tried to blame the tragic Columbine shooting - something that happened a full six years after the release of Doom- on the game.
While Wolfenstein 3D started moving the gaming audience towards the FPS genre, Doom sealed the deal, truly popularizing it. It was also the birthplace of gaming's most amazing weapon, the BFG 9000.