A Nightmare on Elm Street ★★★★★

Remains, conceptually, one of the absolute best horror stories of all time. The fear of fear; a monster that inhabits your subconscious, knows your most intimate thoughts and fears, and exploits them. A monster that feeds off of your insecurities, forcing you to either face them or perish.

Everyone needs sleep, and nobody has true control over their subconscious. Literally any living human is eligible to be haunted by Freddy. I can't think of a more universal story of fear, insecurity, and what happens when you feed fear with fear.