I have very good moments and memories of the arcades, and would like to share some of it's more unreal ones;
When i was about 13, a new game was brought by my local arcade owner, it was Operation Wolf.
We were a lot of teenagers playing at it, spending a lot of days and coins. And no one finished it, even with lots of continues. All i could do is see a glympse of level 3
One day, an unknown man came (we used to know pretty much everyone coming to this arcade), put one coin, and destroyed everything from start to finish. Everyone was amazed. (we were like 20 people around him).
I've never saw him again.