When it comes to football.......the most depressing loss I can remember is the 2005 game at KU to win the north. If sports overall......I was thinking Hampton or UAB, but that was more anger than depression. The 1997 last second loss to UCLA in the sweet sixteen takes the cake for me. Although the 2000 "double foul" loss to MSU it up there.
Today after the game it was like......great season guys. Then I remembered it's not over! So absolutely no depression today.
KU and MIZZou in 04/05 piss me off way more than today.