These are movies that I still find scary from wheb I was a kid in no particular order:
THE BLOB: the original starring Steve McQueen. It broke the canard rule of monsters it did not make any noise. You never heard the blob coming. Plus its ability to get into a room was a nerve rattler.
THEM: the grand daddy of all atomic mutant of the 1950's, starting with giant ants. As I said with the Blob the chirping the ants made was a sign of danger. Policeman Ed Blackburn is at the scene of a murder, he hears the chirps. He walks outside and then he passes a window. The chirps grow faster, then a series of rapid gunshots, a scream and fade out. What works is that it is treated a logical, the authorities quickly dismiss an escape lunatic. They wold have been alerted to an escape and Blackburn was a track shot and one of the victims fired four shots from a rifle before the killer bent the rifle.
What it really scary the ants were portrayed by giant puppets. Like the ants on the SS Viking are battling the newly hatch hive. You see the people grabbed and screaming. It made seem more real.
WAR OF THE GARGANTUAS; this sounds likea generic Toho Giant Monster, this is a sequel to the film Frankenstein Conquers the World. It is a battle between two brothers that one is good and kind, the other is mean and evil. It is the movie where the Green Gargantua eats people and spits out the victims clothes. That is how is best remembered, even Brad Pitt mention this at the oscars. The thing that made them seemed scary, they did not have glassy of dolls, the actors used their real eyes which gave expression to the monster. When the Green Gargantua was on land and attacking in the countryside he approached a pig pen full of pigs. The Green Gargantua is drooling. This was so scary to a kid, and that song in the film The Words Get Stuck In My Throat and some art I did for Monster Interlude Series.
PYSCHO: the film that Alfred Hitchcock made people give up taking showers. It still is scary even if you have watched before, I still jump when Martin Balsom leaves the film. Anthony Perkins performance gives you the creeps.
CURSE OF THE DEMON: A film where a skeptic is curse by a Black Wizard to be killed a demon. Most of the horror is unseen just a feeling of dread and an ominous cloud that seems to stalk Dana Andrews. There are a couple of jolts that are just red herrings like the hero running into a branch.
JAWS: the movie that scared people out of the ocean and sometimes the bath tub. Again when Steven Spielberg directed was a masterpiece of terror. When Sheriff Brody and Hooper find a boat wrecked. Hooper swims over to it, and when the body fell into view. Me and my sister still jump and scream.
NIGHT OF THE LIVING DEAD: the original zombie movie by George Romero. The films does not show much, but it is still chilling. The actors add to tension.
It is incomplete list but these pop up foremost in my mind at what screamed me.