Does that guy who sits in Main Stand still do his "ATTACK ATTACK ATTACK" shout?
My favourite was an ICT v. Dunfermline game a few seasons back, which was particularly boring. 88 minutes of near silence in the North Stand until one brave soul began with "Give me a 'C'"... met with near silence... then a moment later someone shouted "Quiet you, i'm trying to sleep!"
Another would be the time someone went "Give me a C, Give me a A, Give me an L, Give me a.......uhh...em....E" That 2 second pause trying to work out what the next letter was resulted in a 1000 or so folk laughing and cheering their way through the 'Y'