The 500-0 clean sweeps that occurred in the game, one of which was the April Fool's Day episode. One of them came with a perfect 10-word Bonus Lingo round.
Anytime anyone gets $100,000 in the Bonus Round in Bill Engvall's version. 90 seconds, no bonus letters, and a computer that sometimes takes several precious seconds to register an answer (probably on purpose, considering what's at stake). Usually the teams are frozen in place afraid to blurt answers out, but there was at least one winner.