I once crashed a major financial providers website by putting a $ at the end of a URL.
It wasn't until 2-3 week later, that they asked me what I'd done during the test, and I checked the logs, and genuinely remember being so fed up that I didn't find a bug, that I randomly bashed the keyboard, and pressed enter. The character was passed to the backend database and crashed it.
Three dead dudes arrive at the pearly gates. St Peter asks the first "What vehicle did you drive before you died"?
"A Jeep Cherokee", replies dead dude one. "OK, it's the down escalator for you then, mate!" says St Peter, "You're for the hot house, you gas-guzzling, planet wrecking 4x4 driver"!
St Peter asks the second guy the same question. "A Toyota Prius" says dead dude two. "Down escalator for you too, sonny" says St Peter. "No room for sanctimonious, hemp-underwear-wearing, proselytising loonies here"!
St Peter asks the third dead guy the same question. "A Land Rover" he replies.
St Peter scratches his beard and thinks for a moment.
"Come on in, son" he says, "You've suffered more than enough already"!