It could be a Hitchcock film, Kubrick, The Scream franchise, or Halloween? What was it?
For me, it was the Nightmare on Elm Street films, particularly #1.
There's something brilliant about a villain that can only kill you in your dreams, with razor sharp blades that he wears on his hands and oh, by the way he has a severely burned and grotesque face.
I was 10 when I saw it for the first time and I slept with a butchers knife under my pillow for a week afterwards.
What about you? What's your pick?