From: Gears of War (Xbox 360, PC, 2006)
Possibly the ugliest enemy in a game filled with ugly enemies, the Berserkers of Gears of War are huge, destructive and - if you don't know how to deal with them - nothing short of horrific. They're also blind and have a disturbing habit of standing around sniffing the air when they don't know where you are. Once they figure that out, however, they'll roar toward you like a freight train, smashing through stone obstacles in an attempt to reduce you to bloody bits. They're at their absolute scariest when you're running from them, and all you can hear is the engine-like noise of their running drawing rapidly closer.
As if all of that weren't frightening enough, the Berserkers are nigh-indestructible, and getting them into a situation where they can be killed usually takes quick thinking and footwork. In the case of the first one you meet, for example, you'll need to lure her outside by tricking her into smashing open a path for you. Of course, to do that, you'll need to actually stand in front of whatever it is you want her to smash through, only jumping out of the way at the last second. Of course, by the time you figure that part out, you're almost guaranteed to have been torn apart by the creature at least a few times.
Dead Rising (Xbox 360, 2006)
There's something about chainsaws that awakens some deep, primal fear in the human heart. Maybe it's the ominous revving, or just the thought of dozens of tiny blades messily tearing through flesh. Whatever the case, Adam MacIntyre carries two of the damn things, and he's a clown to boot, thereby neatly combining two lurking childhood fears. He's also unclear about his intentions at first, giving us a feeling similar to what happens when a friendly acquaintance starts "joking" about how he's going to brain us with the shovel he's holding.
At any rate, it's hard not to be at least a little nervous when he starts advancing on you while juggling his saws. And when the fight actually starts, and he leaps and giggles while arcing the saws around to turn you into a blood-spraying mess, you'll want to immediately put as much distance between you and him as possible, even if it means having to contend with the stupid, poison-filled balloons he bounces your way.
We'll probably never know what Adam's deal is. Was he driven insane by Dead Rising's zombie apocalypse, or was he this way when he was allowed to be near children? Either way, his roaring chainsaws and perfect makeup scare the shit out of us.