The rules are simple:
Start off by granting the wish above you. The thing is, you can't just grant it you must also throw in a twist. Examples:
Player A: I wish I had a cute puppy!
Player B: Granted, but although it looks absolutely cute and adorable it attempts to take your hand off the moment you try and pet it.
Player Y: I wish I could learn to sky dive.
Player Z: Granted, but you never learn how to deploy a parachute. Your first sky diving trip ends with a splat.
Be original. Try not to corrupt everyone's wish with them dying. After corrupting the wish make your own. Simple. I'll start.
I wish I lived in a mansion.