If you've been around UK football long enough, you know it's tough to even begin making lists like this. There've just been so many embarrassing losses it's tough to rank them--especially because most are games we try to erase from our memory.
But, fwiw, I think my No. 1 most embarrassing might be that game against Arkansas at the end of the Joker era--in the first half Arky ran up a 49-0 lead, and the game was so pathetic that midway through the 3rd quarter we decided to quit and cancel the rest of the game while blaming it on the rainstorm.
Seriously, that happened. Closest thing ever seen to the "mercy rule" in major college football. The first two and half quarters were just so unbearably awful that we decided the second half should not be played. This happened not in a little league or girls softball game, but in an SEC football game in the 21st century.