The Accused 1988. They made us watch this freshman year of college for a womens study class. I had to walk out and the teacher came out to ask, are you ok. No, I just turned 18 and your making us watch bar rape scenes.
shareThreads (1984) Still to this day.
The Thing (1982) Still have occasional dreams about this one, It never ends well for me or anyone else.
Movies don't really give me nightmares, not that I'm aware of anyway.
I remember sneaking to my neighbour's house to watch The Omen when I was far too young for those sorts of images, probably about 7 or 8 years old. No nightmares but I found it hard to go to sleep for about a week.
Wolf Creek really unsettled me to, because it was based on murders that happened pretty much in my backyard and because John Jarratt was so convincingly evil as Mick Taylor. Not a film I'd recommend watching on your own.
No movie ever gave me nightmares...
Exorcist... ok... screw you! That was some fucked up shit!!!