Films with similar endings as Godzilla where the good guys have won and the monster is dead.... but one egg survives and a baby Godzilla leg pops out... oh no! Look film making cnuts, you couldn't scare me once in 2 hours so that is hardly going to make me plop my pants.
I remember going to see the Exorcist at about age 13, and the cinema had nuns & priests outside trying to dissuade us from going in and sprinkling us with holy water. I think that made it seem much more scary & important than it was, and then all the rumours of subliminal messages etc, made me a bit spooked for a while.
Didn't do a lot for the 15-yr-old guy who'd taken me who obviously hadn't read the basic first date rules properly...
Visitor Q definitely wins the 'fucked up' stakes: incest, rape, murder, prostitution, domestic violence, dismemberment, disembowelment, necrophilia (complete with emptying of bowels and rigor mortis), excessive nipple milking, ...and hitting heads with rocks!
Though somehow that list doesn't seem to do the film any justice!
I agree with PTP, Max Schreck in Nosferatu is still spooky, despite being a silent movie. There was a spin-off movie about Schreck based on rumours about his 'odd' behaviour, forgotten what it's called though.