In Fable 2, my dog teleported into the Cow & Corset and then backflipped down the stairs like slinky.
In Red Dead Revolver, I pointed a gun at an enemy's face and he holstered his own weapon and nodded to me. This has happened several times with the same enemy.
In Blood Omen 2, there's a cheat code that lets you start the game with the Soul Reaver and the Iron Armor from the first game. There's a certain point in the game where, if you're using this cheat code, the Soul Reaver will be resting on Kain's shoulder and pointing forward, poking Vorador whenever he gets too close.
In many modern games, corpses will sometimes twitch and shake as though possessed.
In Return to Castle Wolfenstein, one of the earlier missions has you meet up with a wounded member of the Kreisau Circle. You can shoot him dead, or even blow him to pieces, and his corpse (or pile of gore) will continue to speak, lamenting that he can't accompany you in his condition.
Once when playing Fable 2, without having ever committed a crime, everyone suddenly hated me and kept referring to a massacre that they seem to think I'm responsible for. In another game of Fable 2, also without having committed any crimes, the guards in Knothole Island confronted me with 20 counts of murder, a theft, and 3 parole violations. Since I don't have an enormous pile of gold with me and the guards think I violated parole several times the only option is to resist arrest, so I can't even finish the quest there.
In Planescape: Torment, it's possible to repeatedly extort money out of a woman in the Smoldering Corpse bar. I've gotten almost 100,000 coppers out of her before.
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You have your way. I have my way. As for the right way, the correct way, and the only way, it does not exist.