Even though the film is in black and white, it doesn't lessen the impact when it comes to the film's psychological and physical horrors. Get ready to be shocked by some ghastly gore as the zombies feast on their victims, but the true horror comes with Romero's poignant social commentary about the times -- an essential through-line that connects every zombie movie he's made since.

1. "The Exorcist" (1973): Thanks to the character's guttural voice, her decaying face, her spinning head, and spewing, green vomit (in addition to a string of vile, blasphemous unmentionables), Linda Blair is horrifying as the devil-possessed teen Regan MacNeil in director William Friedkin's horror film classic.

It's arguably the scariest movie of all time, and if you watch it, count on it taking years before you can scrub the images of the film from your brain. May the power of your memory compel you to forget anything you've seen.