The funniest joke in the world was written by British jokesmith Ernest Scribbler in 1944. After he read it back to himself he died laughing. His mother, discovering the body, read the joke thinking it was a suicide note and promptly fell down dead. A policemen sent into to Eric's house to retrieve the joke, also died after reading it. After successful trails with the British Army who realized the joke's potential as a weapon, the joke was translated into German and used in battle. Eventually the joke was captured by the Germans who try to write a "killer" joke of their own but failed. After the end of the war all joke warfare was banned by the Geneva Convention. The last paper copy of Ernest's joke was buried in Berkshire, England under a monument that bears the inscription, "To the Unknown Joke".
I cannot reveal the English version of the joke for fear of accidentally killing you, but the German version is as follows:
"Wenn ist das Nunnstück git und Slotermeyer? Ja! Beiherhund das Oder die Flipperwaldt gersput!"