Thought i would add this scene in from Final Destination 5, remember watching it at the cinema and quite a few people cringed at it. So many different death scenes in them but this one i always remember.
Not really a gore scene, but at the time it scared the shit out of me. Friday the 13th Part 2 (1981) at the very end when Jason jumps threw the window. Then the credits roll.
Ever since then though there have been so many copy cats of this type of thing. All is calm at the end of a movie and everyone thinks the killer is dead and gone. Then he comes out of nowhere. Then the credits roll. I'm not sure if 13th part 2 was the first to do this type of thing, but everytime I watch one of those types of movies now, I already expect it. So it's really not that scary anymore. Because it always happens, then it makes me think of Friday the 13th part 2.
also not a gore scene but for making you jump, the end of the original Carrie when her best friend was at her grave site all peaceful background music playing then al of a sudden BLAMMO!!! her hand comes up out of the grave and starts pulling the girl in!! scared the beejumpin jeebus outta me!!!
Overall though the movie that fuked me up the most was the original Nightmare on Elm St. I rented it on VHS. My parents went out to dinner. I was 14 yrs old at the time. My parents stayed out pretty late that night and I refused to fall asleep. Even after they got home, I stayed up all night long until the sun came up. I can still remember as my eyes began to droop and how I fought it and fought it until I fell asleep.