For the "in person" experience, I've had many over the years, but as I have communicated in the past, the 2008 game against FSU where we saved the game at the goal line with Cooper's forced fumble is right up there with any I have seen. That is mainly because it was me and my late son, and we had a truly wonderful time at that game.
I was also there for the 2009 win at night over VPSIU, but for that one, I was by myself. It was great, but the one with my son was better.
Watching on TV, the 2014 UGAG game where Harrison tied it up with the 53 yard FG, and then we won in overtime is right up there at the top. (probably tied with the win over UGAG in 2008)
Of course, I loved the 1990 season and the natty, but obviously back then, we did not get the bowl game we probably deserved and beat a good (not great) Nebraska team to finish an undefeated season.