The Strangers/Nightmare Fuel

In case you didn't already realize it, Joanna Newsom's "Sprout and the Bean" is terrifying (especially on vinyl, especially when it skips). As an added bonus, at first it seems like a cute children's song (with bizarrely unnerving music, granted), which is creepy enough... until you pay attention to the lyrics and you realize that it's probably just as disturbing as the movie.
The parts with the lingering shots, with lit parts of the scenery and the shadowy parts both providing a good contrast. And then a lone figure just emerges from the shadows, but lingers just out of complete view, and just stands there...staring.