The Doom series (PC, PS1, SNES, GBA, Xbox, 360, Game Boy Advance, Atari Jaguar, et al) began not so creepy, but offered satisfying gameplay for years, and really kicked off what the first-person shooter genre could become. Imps, flaming skulls, zombified troops, cacodaemons and much more laid between you and liberating Mars from the maw of hell. Chainsaws, shotguns, bazookas, plasma rifles, and the legendary BFG-9000 should make the task easier, though by no means easy. Get your ass to Mars, soldier!
Prototype (PC, PS3, 360) spent years in development at Radical Entertainment (the whiz kids behind the similarly enjoyable Hulk: Ultimate Destruction), and turned out to be a hell of a ride, in my opinion. You wake up as Alex Mercer in a Manhattan morgue, about to be cut open for autopsy, with no memory of how you got there, or the events of the last several months; one thing is for sure: everybody wants you dead. What follows is a devastating infection of the citizens of the Big Apple that the military can't control. Everybody's against you, from zombified citizens and a handful of other infected creatures (Hunters, Hydras, and the malevolent Elizabeth Greene) to the military and Blackwatch mercenaries, it's more than enough to kill a man. But Mercer is a man no longer. The infection has given him the ability to shapeshift and perform incredible acrobatic feats like sprinting up the sides of buildings and gliding through the air. Need to get into that military installation? Consume a commander and assume his identity, sneak in, and cut loose. Want to lose pursuers? Consume a citizen, drop out of sight, morph into them, and you're home free. You are the monster in this title, and from razor-sharp claws to giant club-fists, a bladed tentacle arm, aptly named devastator attacks, skyjacking helicopters, stealing tanks, and more, you are truly a force to be reckoned with. After an hour with Prototype, every other game just feels tame by comparison. Let the rage out; it's gonna be bloody.
Resident Evil 5 (PC, PS3, 360) is the latest in the survival horror genre. I suppose you're wondering why it's not up in the Bump in the Night section. Honestly, the series feels more about gunplay and blasting enemies apart than about an overall sense of dread or tense moments where baddies leap from nowhere. It's a perfectly serviceable shooter, though ammo shortages early on can make levels more challenging than you'll find them on repeat play-throughs. The visuals are top-notch and co-op play adds to the blasting fun, but by no means would I call this game particularly scary. Gross at times, sure, but unlikely to give you insomnia.