Scariest game in my opinion would have to be Clocktower: The First Fear for the Super Nintendo. Although it was never released in the United States, they did a remake of it for the PS1, but they changed around the story a bit and added some things. I have yet to play it, but I think that the original would be better.
Here are some screenshots of the game:
Scissorman
Nice fog effect.
The story:
"Tragedy struck Jennifer Simpson at an early age. First, her mother passed away. Then her father, a medical doctor, mysteriously vanished while answering a late night house call. Seemingly abandoned and with no surviving relatives, the turned custody of Jennifer over to Granite Orphanage. Although quiet and reclusive, Jennifer manged to make friends with a small group of her fellow orphans: Ann, the prankster, the insecure Laura and the pessimistic Lott.
Then in September of 1995, a woman named Mary Barrows visited Granite Orphange. The wife of the wealthy Simon Barrows, Mary Barrows had come in her husbands stead to adopt children for their family. At first Jennifer and her friends were afraid of being separated. However, they were shocked to learn that Mary Barrows planned on adopting all four of them! What followed seemed to come right out of the pages of a fairy tale. Their new stepmother led Jennifer and her friends up the lush country road to the "Clock Tower" mansion. The townspeople called the Barrows mansion this because of the large clock tower built into the roof.
Mary took Jennifer and her friends inside the gigantic mansion that would be their new home. She tells the children to wait there for her in the main hall while she went to get her husband Simon. At first, the children were excited and waited patiently. Soon they realized that Mary has been gone for an awfully long time. Finally, the girls suspect something was terribly wrong. Jennifer told the others to wait for her and decided to go find out what happened to their new Stepmother.
Jennifer was searching for Mary in one of the mansion's long hallways when suddenly the lights went out and there is a blood curdling scream. She rushes back to her friends only to find the main hall deserted. Desperately, Jennifer searched the nearby rooms looking for her friends. Then a being straight out of a nightmare revealed himself, a madman wielding a giant pair of scissors! She thought she'd escaped him, but he kept stalking her and nothing seemed to be able to stop him. Now, you must assume the role of Jennifer to find a way to elude the murderous Scissorman, rescue your friends and escape the Clock Tower mansion before it is too late!"
If you want to play the original, you'll need a SNES emulator, the rom, and a translation patch...unless you of course know japanese.
Great game nonetheless.