For whatever reason, I tend to be more excited about victories early in the season, or non-NCAA tournament games. Maybe I'm a pessimist by nature, but I spend the majority of tournament games, and the hours beforehand, thinking of ways that it could go wrong. So, although the games mentioned above usually become more satisfying in hindsight, at the time I feel more relief/disbelief than anything else. The Michigan State game this season was a perfect example of this - it was such an awesome experience that I was in a daze for a solid 24 hours afterwards.
So to me, there's nothing more exciting than realizing early in the season, "holy hell, this team has a chance to be damn good". The Kentucky walloping in Maui a few years ago and the beat down of Louisville in 2009 both qualify in that regard.
But, I don't think I'll ever feel more euphoric after a game than I was when Kemba beat Pitt at the buzzer back in 2011. Part of the reason I felt that way was I didn't feel they had a chance, and had all but written them off by that point. I'll never forget ditching school early that day, dumping my backpack, and literally sprinting the entire two miles home to get there for the second half. Truly a classic.