I'll go with 1980. It was only the second time, but the second time in a row, that OU had won in Manhattan since 1948. OU had lost 31 in a row, obviously, before that epic game on a Wednesday night in '79. Then OU took care of it again, with two buddies and I there in the front row near the OU bench.
In fact, my OU roommate from our frat house got stuck sitting next to a KSU professor who started the bizarro conversation with a false story about how KSU hoops had a better winning tradition than OU football did. Then he'd elbow my friend everytime KSU did something good (even though OU led for most of it), and say, "How'd you like that?"
But, when some Ada freshman named Bo Overton threw up a slinky-like layup to put OU up by 12 in the final minute (the ball almost looked like it hit the undersize of the rim but clung to it and rolled up and over the top and into the net), we had our payback. Jeff told him, "How'd you like THAT?!?" The silence was deafening.