Excellent thread idea, John, though growing up an Aggies, Astros and Oilers fan, my great moments are certainly few and far between

No championships to speak of except for the 'Stros winning the NL last year, and that was more of a relief after Pujols robbed me of a really great moment in Game 5 of the NLCS.
Though I haven't been a fan from birth, the '96 Yankees coming back on the ATLs from 2-0 to win the World Series that year was a big moment for me. Best friend was an NYY fan, and he passed away earlier that spring, so I had a nice 12:1 ticket from Caesar's in his honor that paid off handsomely. Charlie Hayes catching that foul pop along the rail to end Game 6 and win it (plus Leyritz' homer off Wohlers in Game 4) are the most vivid memories in my head.
There are a bunch Aggie football memories in the bank. But as far as games I was in the stands for, perhaps none are bigger than the 28-21 win over Nebraska at Kyle Field in '98. That one stands out even more than the double-OT win in the Big 12 title game against K-State about two months later.
Being in the stands for Don Nottebart's no-hitter in 1964 and Don Wilson's in 1967, both times with my dad and Wilson's even coming on Father's Day.
Game 4 of the 2005 NLDS with the Astros topping the Braves in 18 frames. Chris Burke's winning blast was an incredible high.
And the Oilers' 35-31 win over the Dolphins in 1978 with rookie Earl Campbell leading the way.