WoW Mists of Pandaria Beta: World of Linecraft
The quest all of these players are lined up for (Wisdom of the Ages) is one where, for a while in early beta, only one player at a time could perform; otherwise, all players would be locked out of this quest until the server rebooted. Blizzard has since fixed this bug, but I included it as an example of one of humanity's finer achievements: the ability for dozens of people to participate fairly by standing in line - for hours - instead of cutting in. I did the quest by signing on early in the morning before work when no one else was around.
Screenshot of World of Warcraft Beta game client by Wally Bahny for TechRepublic