Georges Melies' 1896 short "Le Manoir du Diable" is generally considered the first horror movie. Melies, a former stage magician, went on to pioneer early special effects in film.
Over 160 actors have played Count Dracula in the movies, more than any other horror character. The most famous was Bela Lugosi, but others include Christopher Lee, Frank Langella, Gary Oldman, Jack Palance, Gerard Butler and George Hamilton.
The shower scene in "Psycho" is easily the most infamous onscreen murder in movie history. It consists of over 90 individual shots delivered in just 45 seconds--and no single shot ever shows the knife entering Janet Leigh's body.
"The Silence of the Lambs" is the only horror movie to win a Best Picture Oscar. It also provided two of the four performers--Anthony Hopkins and Jodie Foster--ever to win Best Actor/Best Actress Oscars for a horror movie (the other two were Fredric March, who won for 1932's "Dr. Jekyll and Mr. Hyde," and Kathy Bates, who won for 1990's "Misery").
The theme from "Halloween" remains one of the most iconic in horror movie history. It was actually composed by the film's director, John Carpenter, who composed the themes to almost all of his films.