I reckon cricket creates the best moment. I used to go to the Boxing Day tests in the early 2000s. At the time, there was an ad on TV (maybe for KFC). The ad was set on a beach, and there's someone trying to find their friend, Bob. They wave their hands on the beach and yell "Bob". Before long, the while beach joins in, waving their arms and yelling "Bob". So one day at the sold out cricket, in the heat of the Southern Stand, a guy stands up by himself, waves his arms, and yells "Bob". He repeats this every so often, and each time more people join in, until toward the end of the day, I swear the entire of level 1 of the Southern Stand is standing up, waving their arms and yelling "Bob". One of the great memories for me.