[1066AD]

Here's a few suggestions via Google, I suspect the first is the one used on FR:

You're in the brotherhood of soldiers

"Yell if the beer is on sale!"

Youre in the Butt of Sheep

Your Initiation Takes Balls Of Steel

Your In The Basement...Oh Shit

[bruinbirdman]

The google search says "Results 1 - 10 of about 605 for yitbos". There are actually 10s of thousands.

Heck "bruinbirdman" has more than 16,000.

yitbos