Cohen, Levy and the Genie
Cohen and Levy are both in the antique business across the street from each other, and have been for years. Cohen doesn't like Levy - he thinks he's a thief and a liar and an ignorant bum, and says so publicly. Levy thinks the same about Cohen.
One day Levy leaves the door open to his shop and goes out for a few minutes. Cohen takes the opportunity to walk across the street and steal a magic lantern Levy has in the window. He gets it back to his shop and can't resist rubbing it. Naturally a genie pops out of the lantern.
"Cohen", says the genie, "because you have released me from a thousand years of confinement in the lantern, I will grant you one wish - anything you want - money, power, fame, anything. But because the lamp belongs to Levy, whatever it is you get, Levy will get twice as much."
"You mean," says Cohen, "if I ask for a million dollars, Levy gets two million?"
"All right, genie," says Cohen. "I know what I want."
"I wish I were half dead."