Fear any of them...very scary gave me nightmares. also when i was like 9 me and my friend played the "Libary" on Halo:Combat Evolved...pretty scary at 3 in the morning.
Actually I don't fell any fright when playing horror games because it's only the state of the mine that thinks it's scary but not. I am not gonna say I am not afraid of anything but the games are just surprising like when your walking down an empty room that builds up tension then suddenly a dead guy appears out of nowhere and that sudden appearance of dead guy will increase the tension until it has no where to go but out.
if you google it you will find that 70% of the people under 18 find regenarators th most scary monster in any other resident evil game. even other games.