Clock Tower for the PSX.
The voice acting & dialogue is atrocious, and the plot has that dumb charm that accompanies 80's slasher flicks, but it was freaking awesome.
You know that style of survival horror that games like Amnesia are often lauded for, where you can't fight and can only hide and pray that your enemy doesn't get wise and rip the door off of your warderobe of choice, leaving you helpless? Clock Tower was doing that in the PSX era (SNES era as well if you go a bit further back). It was a gem lost amidst a sea of Resident Evil clones on the PSX, despite having nothing in common with it (besides the god-awful voice acting). Another thing is that while encounters with Scissorman could be triggered by the player's actions, they could occur at any time. Thus, even the menial item hunting with no sound save for your hero/heroine's footsteps became extremely tense and creepy, because you knew that at any moment, the sound of clashing shears would be heard just outside the room, and you'd suddenly be running for your life.
While a lot of people think Scissorman is kind of goofy nowadays (and to some extent, he is), I think that he's actually benefeited from his age; his jagged, twitchy limping has become much more disturbing and inhuman in this age of smooth, beautiful animation. That, along with his remarkable tenacity, adrenaline pumping theme music, and the aura of pure menace that accompanies him wherever he goes makes him one of my favorite villains.