The best moment in any match that I have been involved in was 2009 Newton Semifinal 1-2. The number 5 seed alliance, 1507, 121, and 177 was down 1 match to the powerhouse 1 seed of 1625, 234, and 768. It was a tight, defensive match, but at the end, 177's human player hit a buzzer beater full court shot (literally from one corner of the field to the far alliance wall) that somehow bounced into 234's trailer as time expired. In the end, it didn't change the outcome of the match but it was the most exciting moment I've ever seen in FIRST. You can see the video if you go to
http://www.rhodewarrior.org/video/index.html and click 2009 then Semifinal 1 Match 2.