From: Resident Evil 3: Nemesis (PSone, DC, GC, PC, 1999)
Taking place parallel to the events of Resident Evil 2, Resident Evil 3 is saved from side-story status by one creature: the Nemesis, a lab-created hunting horror tasked with eliminating all members of the STARS special police group. And because your character, Jill Valentine, is one of those members, things don't look too good on your end.
A dramatic departure from the zombies and other dimwitted enemies that haunted the series up to this point, Nemesis is a towering juggernaut that chases you relentlessly (sometimes with a missile launcher) and regenerates every damn time you think you've killed him. He appears only at pre-determined moments, but unless you know where and when to expect him, it feels like he's always there, tracking your movements and waiting for the right time to bust through a wall and pierce your skull with a virus-packed tentacle.
Knowing Nemesis was constantly at your heels gave RE3 a sense of deep dread that the other games in the series lacked, and the fact that he'd come back even after sure-fire deaths turned each victory into a temporary act of escape instead of a triumph. And if that's not enough, just look at the ugly bastard. Is that a face you want to see biting into your flesh? No, we didn't think so.
From: Fatal Frame II: Crimson Butterfly (PS2, Xbox, 2003)
Considered by many to be the moodiest, most frightening horror game ever made, Fatal Frame II is the story of two teenage girls trapped in a haunted Japanese village, and as such it's crammed to bursting with uniquely eerie ghosts. And while all of the game's translucent, disfigured, glassy-eyed horrors are scary - something made worse by the fact that your only weapon against them is a camera - none of them are more terrifying than the "Kusabi" found in the village's crumbling Kurosawa House, and that's a hell of a distinction.
This Kusabi - the powerful ghost of a sacrifice victim, also known as Rope Man - is huge and horrifying, and your camera won't work on him at all the first time you meet. What's more, if he touches you - which he'll do immediately, unless you race to the nearest door in a hurry - you'll die instantly.
Eventually, you'll be able to face him. But after he first appears, he'll simply hang around the burned-out room you find him in, floating around menacingly and waiting for you to set foot in the room so that he can close his icy hands around your throat and rip the life right the hell out of you.