Red Dead Redemption: Undead Nightmare/Nightmare Fuel

You were forced to kill your family friend. Your own wife and child have become ravenous, flesh-eating ghouls, as have thousands of people across the West. Once serene (well, for the most part) settlements have become fortresses against the shambling hordes, their residents dwindling in numbers. Ammo, as well as allies, are scarce. And you've got to set out into the deadly, zombie-filled land to find a cure and possibly save who you can. And those animals that gave you such a hard time in Red Dead Redemption? They're zombies now.
Some of the random events you can come across are pretty unsettling. From a group of undead devouring a pile of corpses, civilians transforming right before your eyes, deranged cannibals who invite you for a "bite" and turn their guns on you if you decline, and more. One of the more disturbing ones is coming across a sobbing man sitting next to a dead man, likely a friend or relative. The dead man rises as an undead and the living man is forced to shoot him...right before turning the gun on himself.