20. Dawn of the Dead (1978)
Memorable quote: When there's no more room in hell, the dead will walk the earth.
Scare factor: Whats scarier than watching one of the remaining humans slowly transform into a zombie? Realizing that the zombie-in-progress is one of the only people who can fly the helicopter to get you out of there. George Romeros epic-scale zombie apocalypse movie is really the only film featuring the living dead that really captures the pure hopelessness of a global zombie apocalypse. It has spawned sequels and knock-offs and inspired video games, but nothing beats the original.