#3. NIGHT OF THE LIVING DEAD (1968)
The original and still the best. Even before it would become a cultural icon, with academics and noobs alike assigning various meanings to it (the black hero, the white woman, etc), George Romero realized that the undead was not frightening because they were fast or that they were hard to kill, but because they were us. Romero didn’t need zombies that ran around like speed freaks, or were infected by some viral blood to made them behave like crackheads; his zombies were horrifying precisely because they were so slow, so ordinary, so persistent, but there were just so, so many of them, and sooner or later, they would get you.