15 Horror Movies You Really Shouldn't Watch Alone

12. Paranormal Activity (2007)

Though the Paranormal Activity series ultimately ran itself into the ground with a series of low-effort sequels, the original movie was a major breath of fresh air in the found footage genre.

What really made the film so damn effective was its down-to-Earth minimalism: what we're watching really does feel like the home videos and surveillance footage of an actual couple inside their (distractingly large) home.

The genius of the movie's now-famous blue-tinted night-time surveillance scenes is that they generally require director Oren Peli to do very little. The audience will populate the sparse screen with most of the terror themselves, and beyond a few basic prop tricks, the horror largely resides in the viewer's mind.

What you don't see is so much more terrifying than what you do - confirmed by the final sequel revealing what the demon looks like and sucking all the tension away - which combined with believably rattled performances from Katie Featherston and Micah Sloat makes this an all-timer "bump in the night" movie.