IIRC, on the first season of Trebek's Jeopardy, all three contestants bet all their winnings on FJ and got it wrong. Alex said there would be three NEW contetants on the next show. This was 1984, and the memory is a bit fuzzy. The strategy of FJ wasn't as established as it is now.
On Rayburn's syndie MG, a couple of contestants didn't match any of the Super Match answers and won $0. I remember Rayburn saying "shake my hand" while in the background Brett was saying "Doesn't he get $100?" and someone saying "Not anymore." Might have been CNR.
On Match Game PM, a couple of contestants won $0. IIRC, one guy got $100 and Rayburn said "With your luck you'll get mugged on the way home." For one lady they played a question where each celeb she matched got her $100. I beieve she matched all six.