Doom

Doom (1993) remains the most influential first-person shooter ever made. Its shareware version was downloaded over 10 million times and installed on more computers than Windows 95. The fast-paced demon-slaying, atmospheric levels, and network deathmatch mode redefined PC gaming. Its deathmatch mode set a competitive standard that even Street Fighter II's arcade battles couldn't match in online penetration. By 1995, Doom had sold over 2 million retail copies and spurred an entire genre, outperforming #6's static fighting arenas in movement freedom and replayability.