1974 - No doubt
It was my first year in college. I came home from school to my parents in Dallas. Dad was a VP of sales and had season tickets to the Cowboys, Rangers, etc. He asked if I wanted to take my girlfriend. We went to the game.
Here is what Wikapedia has to say about that day:
"Clint Longley" is best remembered for his performance in a Thanksgiving Day game in 1974 against the Washington Redskins. Longley then a rookie, came into the game for an injured Roger Staubach with the Cowboys trailing 16-3 in the third quarter, and facing elimination from the playoffs. After hitting Billy Joe Dupree for a 35-yard touchdown pass, he led the Cowboys on a 70-yard drive capped by a 1-yard Walt Garrison touchdown run. Finally, with the Cowboys behind 23-17 and with only 28 seconds left with no time outs, Longley hit Drew Pearson down the middle for a 50-yard hail mary pass touchdown which gave the Cowboys a dramatic 24-23 come from behind victory. Because Longley had no expectation of playing in that game and was completely unprepared, Cowboys lineman Blaine Nye sarcastically called his winning effort "the triumph of the uncluttered mind." The game was named the second-best in the history of Texas Stadium by ESPN in 2008.
That girlfriend married me after we graduated. We've been married 35 years. Still watching the games on Sunday when we can as we now live in the Philly area.