This post does not necessarily concern Halloween themes, but nevertheless it seems an appropriate time of the year to pose the following question --
For me, the answer is immediate -- Alfred Hitchcock's The Birds. I saw it on TV when I was little and it scared the bejesus right out of me.
Like all of Hitchcock's movies, there was nothing excessively graphic or gory about the film, but the Master of Suspense made his audience visualize the terror and violence in their minds -- which is ten times worse!
More or less around the same time that I saw this movie (although I can't remember specifically if it was before or after), I developed a major phobia about things flying around my head. The causal incident was an ugly and traumatic episode with moths in a confined space which I could not escape. But this movie, regardless of when I actually saw it, certainly didn't help the situation.
This phobia still plagues me. I cannot set foot in a butterfly house at a zoo or botanical garden, nor can I tolerate any birds or other creatures flying around my head.
So what about you? Any movies that scarred you for life? Spill your guts in the comments (but not literally though, please) . . . .