I was already a teenager, but The Blair Witch Project made me quite scared of the forest after dark. Didn't help that we lived right next to a completely overgrown property (it essentially was a forest... a whole family of foxes lived in there) with an old unused house in the middle of it.
Anyway... the psychological horror of that movie was intense. Jump scares I can get over, but the perceived fear of the actors and that ending in the cellar burned itself into my brain.