I was living in Champaign, Illinois when that Bear disaster took place. It was brutal. Surrounded by Bears fans with no Cowboys friends around. Plus, the Bears went on to win the Super Bowl and there was all of that "Super Bowl" shuffle stuff. I forget why, but before a playoff game the team stayed at a hotel connected to a mall two blocks from my apartment. Bears crawling all over the place. I was in hell.
My list:
1. January 31, 1967 The Ice Bowl
2. Each of the great Cleveland disaster playoff losses in 1968 and 1969. Brutal losses with a long off-season that followed. Back then the league did this stupid thing where the two first round losers played in "The Playoff Bowl", which was, of course meaningless. Dallas after getting embarrassed by the Browns again in the real playoffs got destroyed by the Rams in the Playoff Bowl 31-0. It was physically painful. I had to leave the house during the game because it was so painful to sit through.
3. Super Bowl V We was robbed.
4. Ninth game of the regular season in 1970. In what seemed like a must win Monday night game against the Cardinals Dallas imploded 38-0 Horrible to live through. Miraculously, Dallas, lead by a truly great defense, didn't lose another game until Super Bowl V.
5. Landry's firing.
6. Staubach's retirement.
7. The day Tom Landry died.
8. *Edit* The Dwight Clark catch.
And these aren't single events, but:
8. The Dave Campo years.
9. Watching that clown Barry Switzer stain the sidelines where Landry once walked.
10. A long list of Jason Garret failings, lead by the time that he iced his own kicker. I just sat there stunned for an hour saying over and over again "he iced his own kicker."