Certifibly insane:

Pally - "I refuse to use any abilities with the word 'light', 'hammer', or '*veng*' in the name"
Hunter- "I am confident I'll achieve 10k DPS on HMICC using thrown weapons and gratuitous use of both Mongoose bite & raptor strike"
Priest - "I really dislike healing, and the shadow tree, but I'm a DPS that will never die, even while standing in the fire. I have master at arms, use DPS weapons, and always bring the lightwell raid buff"
Warlock - "DoTs are for DKs. Pets are for Hunters. I bring the high cast nukes that get the big numbers. I promise to Soul Fire until I'm out of shards each encounter."
Mage - "My tree & glyphs are set up so I can take the least amount of damage while bandaging the members of the raid. I was 3rd in HPS in a Naxx encounter (it's because blink is OP :D)"
Rogue - "I personally dislike being out of stealth, so I make sure that I only use the most powerful opening abilities and then vanish on cooldown."
Druid - "SQWAK. I'll let you pet me in any form. a/s/l?"
Warrior - "I feel slighted that Blizzard has not backed up my personal spec of choice, Fury-Staff."
DK - "Survivability is key in raid encounters, so I always use the presence with the most damage reduction. I prefer to attack at range, so my spec & glyphs are very homebrew."
Shaman - "I've actually set up my computer to run my shaman without my input whatsoever. I have the tank on focus, so the melee should be near him, and the ranged near me. I've found this is the best, most effecient way for Chain heals to be distributed around a raid of any size"