If, like me, you usually avoid the horror genre, you still probably have a list of games have have ratcheted your creepy-meter to full throttle. Here's mine.
5. Halo: Combat Evolved - 343 Guilty Spark
Admit it: the first time you met the Flood, you were a little freaked out. By now, their pulsing gray flesh, their tentacles, and their bloated sacks full of parasites that burst if you get too close probably fill you with nothing but mild annoyance: but there was a time when Halo was the cream of the console gaming crop in terms of graphics, and you had probably never seen a monster so vibrantly and disgustingly alive. This would have ranked higher were it not for the levels titular character, the Forerunner A.I. Guilty Spark, whose voice alone is enough to suck most of the tension and mystery out of the whole situation.