"Day 10 - Your favorite psychological horror film"
Simply put: "Jacob's Ladder".
You might say it's not REALLY a horror film. Well, let me ask you: don't you find the story of a guy who was in Veitnam, now living in New York City, and constantly seeing weird ass images like demons or dead people, then being chased around by shadowy guys, pretty scary? Thought so.
"Jacob's Ladder" is such a mindfuck, even if you do know what the ending is. And that's all there is to it.