Mine has to be layer of fear by far however there's a couple that have left me scared ngl. Doki Lit Club is by far the one I try to stay away from the most, I remember seeing gameplay of it at an early age.
The Outlast trilogy stands out to me. Its relentless tension where your only defense is pure instinct and stealth, forcing you into heart-racing, split-second decisions that never let you feel safe. definitely my favorite
