Audiences love a good scare and horror is one of the most popular, as well as profitable movie genres in the theaters. There would, however, be no conjurings, nightmares on Elm Street, or even ghosts that would need to be busted if not for the groundbreaking horror films that laid the terrifying foundation for the genre. Movies like Psycho, Frankenstein, and The Exorcist paved the way for what horror looks, feels, and sounds like today.