Playing on a Minecraft creative server and talking on Skype with 3 other friends, and we were building a pyramid. Eventually, I ask "Hey, wanna play Alien Swarm after we finish this?"
"Yea!" Were pretty much all the replies.
After we finish, we begin to load up the game. Everyone joins, and we begin to play on Hard.
We get stuck on the second to last mission (as we lost a person mid-game) and got someone else in. Then the finial mission. Our total death count rises, in the opposite direction of our sanity and patience.
Eventually, we complete it... 5 hours later. 5 hours straight. That's longer then most of the times I play games in one sitting. One of us forgot to eat.