There are those who say that the Squaw Valley game twenty years earlier was an even bigger Cold War upset, but of course sports in general were not as big a deal at the time. I'm not sure that much footage of that game exists.
Just including events that I've attended in person. . .
Wide Right II at the old Orange Bowl in '92. A sea of humanity, strangers hugging, that pointless joy that only nutty college kids can experience. :)
Then there was MSU taking down top-ranked Michigan at Michigan in '89. Been an MSU fan...