I do not regret this one because I was provoked.
I was in car with my farher.
Father: You are big person now so you can go into school/ mall shooting now. Do you want me too buy you a rifle? (he makes fun of my lifestyle).
Me:School/ mall shooting? (I play dumb)
Father: You know, that is when some guy starts too shoot people in public place and then he kills himself.
Me: I would never do that!
Father: I am very glad to hear that.
Me: I am fine with that idea but I would never kill myself. I would turn myself in. In the end.
Father:YOU WOULD TURN YOURSELF IN !?
Me: Yes, so that I could have a trial and see the family members of people which I have killed.
In that case I could laugh at their face or play games with them by saying things like "Your daughter said that she loved you very much".
Oh man that would be the day! Buuuahhhaahhaa
My father did not said a word for the rest of the trip.
But the catch is that I have said the last part with so much passion and enthusiasm(and with a smile). So entire thing was really creepy.
My point: Do not ask a question if you can't live with an answer.
But I admit that my jokes are too cynical-sarcastic and too brutal for many people. Since I am scientific and robotic loner 90% of the time this kind of things are always delivered as a suprise. What boosts the reaction even further.