Eraserhead
What the actual fuck have I just watched. Where do I even begin? The ambience, the sound effects, the atmosphere, the visuals...
This is BY FAR the scariest most unsettling, fever dreamish movie I have ever watched, I literally cried during the end. Wow, what an experience. During the whole film I had the exact same expressions as the main character.
P.S. Please don't watch this.