I had a great season of indoor soccer the winter of my senior year of high school. I hadn't played in 3 years and got a team together to play in the "fun" intramurals league at a local field. I also joined a girls' team and played random games before/after my own if another team needed another female.
One evening I played four games in a row. Scored at least one goal in each game. I just kept going and going.. never lost my momentum. It was a great night.
I also have had some really great personal moments in equestrian competition. My most recent competition involved winning a national championship in IHSA, but my favorites definitely involved beating the pants off of people with expensive horses with my little inexpensive pony (or horse, later) that I trained myself. Even riding at home, those moments when everything comes together and produces something amazing are cherished.