I played Silent Hill 1 as a kid, horrific game, so scary, very atmospheric, there was plenty of reasons why! All this combined made for one of the scariest games i've ever played, not just jump scares , proper in your head scary.
Aliens on the C64, when you enter a pitch black room and the motion detector is screaming at you and the only way you could see would be too fire your gun. To which 9 outta 10 times would show an alien right in your face... made me jump every time.
I don't do horror games at the best of times. But having the choice of either a torch to see OR a weapon. meant I didn't last long playing this title.
Siren Blood Curse
When some of the characters you meet become monsters it's truly terrifying with a great cast of characters and horrible sound effects and music.
The necromorphs looked ridiculous but had a habit of jumping out when you least expected it. Also it gave you enough quiet moments for the tension to build up.
Only being able to see the spirits through a camera lens made things incredibly claustrophobic and tense. The enemies were freaky, for example white robed women with their eyes gouged out and neck bent backwards over their shoulders.
"Dark Spirit [player name] has invaded!" is the scariest text you'll ever read. The sense of panic caused when another player joins your game to hunt you down is overwhelming.
Silent Hill 4
Those damn ghosts that you have to pin to the ground with the sword or they keep following you through all doors etc, and where you're in your apartment (where it's supposed to be safe) and one of those ghosts is coming through the wall.
Resident Evil 2
When walking down a corridor and the zombies arms burst thru the walls iam ashamed to say I soiled my shorts.
Not being able to gun and run. Only having a knife in a cramped graveyard was slightly iratating, the scary part way the god damn zombie doberman pinchers that ran at 100mph! Turned it off and never played a Resi since.
Andrew P Paschails
Not exactly scary but the original Condemned with the lights out and volume up will give you plenty of jumps.
Silent Hill 2
one of those rare games that sticks in your head for months after or in my case years. Rounding that corner in the motel and seeing pyramidhead just staring at you from behind those bars for the first time is one of the greatest moments, not just in survival horror but horror in general.