Back in the early days of GameSpy Arcade, there was a set of pre-installed games called the "Parlor Games." These included the typical Hearts, Poker, card-type games from what I remember. I never liked card games, but I thought it odd that among them was a little gem called Y.A.R.N..
YARN was probably the most bizarre game I ever played, and you could make the argument that it was way ahead of its time. The game consisted entirely of user-generated content, something that no other game has accomplished. It was so simple, yet so fun. It was also VERY immature most of the time, but nonetheless, it was one of the most memorable online gaming experiences I've ever had.
The premise of the game is that you are collectively and competitively writing a story. The room host picks the starting sentence, the default being "It was a dark and story night...." When the game starts, everyone in the room is given a prompt to write the next sentence. After everyone has sent their sentence, they are all returned to the players in random order, minus the originating user. The players then vote for their favorite sentence, not knowing who wrote what. The voting results determine which sentence is added to the story, and how many points are handed out.
Apparently, all of the parlor games were removed due to a "security flaw" that was discovered. It's been years since then, and I've never seen YARN since, or anything remotely like it. It surprises me that they just took them down instead of patching. Does anyone else even remember it?