Doom (1993)
This was always the first game that sheltering parents channeled in bouts of "think of the children" hysteria. Though it's one of the defining games of the 90's that popularized the first person shooter, its reputation was marred by its implication in the Columbine massacre. One of the shooters, Eric Harris, was revealed to have been an avid fan who had created several of his own levels for the game.
