One of the funniest quotes and, I think, one with the longest build up in any of Terry's books has to be the 3 chapter preparation for Vimes statement to Otto Chriek about his "Prints of Darkness" in the Truth.

Certainly a great piece of humour with a massivet "Aaaaagh Factor"

I want to die peacefully in my sleep, just like grandpa. Not screaming and panicking like his passengers.
Don't drink and drive from The Lancre Tavern