Night of the Living Dead, 1968

Can a film be as crazy as its monsters? That was the feeling when moviegoers first saw George A. Romero's Pittsburgh-made zombie classic. Instead of the standard alternation of scare scenes and dialogue scenes (to give the audience a break between shocks), here the walking dead just keep on coming, seemingly by the hundreds, to attack the increasingly hysterical humans holed up in a house by the cemetery. Romero also broke one of the few horror rules left: that children don't eat their parents. After Night of the Living Dead, no social norm was safe.