The pasco loss to Colorado in the big 12 tourney is by far the worst loss of all time. 
It was a meaningless game with an unfortunately miserable ending. Pasco Fiasco is a great nickname though, and the game spawned one of the greatest Collegian Fourum entries ever
"What are you doing over Spring Break? Pervis Pasco told me that he's going to do a bit of traveling."
Quote isn't verbatim, but the original was pretty great at the time.