This is probably my crowning glory.
YouTube - C'thun OMG laser
Little back story, this was our first engage on c'thun way before there were any spoiler sites or boss strats were openly discussed. So the GL is counting down, he gets to 2 and i start saying "WAIT WAIT!" which was an ongoing joke in that guild, some one (usually me) would always interrupt the engage countdown. GL says something to the extent of "FFS, what now" lots of laughing results, I'm the guy that suggests testing agro range. There is a 10 second silence, aside from random giggling, where the GL answers my question by restarting the countdown. Well, one of our mages thought testing the agro range was a good idea. The result was probably my favorite raiding incident ever.