16 hours in World of Warcraft during the opening of the Ahn Quraj gates. It was sheer madness on the server when that event took place and my guild shared the front gates with another, completely duopolizing most of what you were supposed to kill for reputation gains. It was a 12 hour long event, and we had been doing our normal raid runs beforehand.
It was a long, long night.
It was a long, long night.