Guards! Guards!

"[...] a number of offences of murder by means of a blunt instrument, to whit, a dragon, and many further offences of generalized abetting [...]"

-- (Terry Pratchett, Guards! Guards!)

"Have another drink, not-Corporal Nobby?" said Sergeant Colon unsteadily. "I do not mind if I do, not-Sgt Colon," said Nobby.

-- The joys of working undercover (Terry Pratchett, Guards! Guards!)

"'E's fighting in there!" he stuttered, grabbing the captain's arm. "All by himself?" said the captain. "No, with everyone!" shouted Nobby, hopping from one foot to the other.

-- Making Friends and Hitting People (Terry Pratchett, Guards! Guards!)

FABRICATI DIEM, PVNC.

-- The motto of the Ankh-Morpork City Watch (Terry Pratchett, Guards! Guards!)

"Pour encourjay lays ortras."

-- (Terry Pratchett, Guards! Guards!)

"This is Lord Mountjoy Quickfang Winterforth IV, the hottest dragon in the city. It could burn your head clean off."

-- Captain Vimes addresses a band of rioters (Terry Pratchett, Guards! Guards!)

A good bookshop is just a genteel Black Hole that knows how to read.

-- (Terry Pratchett, Guards! Guards!)

There was a thoughtful pause in the conversation as the assembled Brethren mentally divided the universe into the deserving and the undeserving, and put themselves on the appropriate side.

-- The Elucidated Brethren see the light (Terry Pratchett, Guards! Guards!)

All dwarfs have beards and wear up to twelve layers of clothing. Gender is more or less optional.

-- (Terry Pratchett, Guards! Guards!)

All dwarfs are by nature dutiful, serious, literate, obedient and thoughtful people whose only minor failing is a tendency, after one drink, to rush at enemies screaming "Arrrrrrgh!" and axing their legs off at the knee.

-- (Terry Pratchett, Guards! Guards!)

People who are rather more than six feet tall and nearly as broad across the shoulders often have uneventful journeys. People jump out at them from behind rocks then say things like, "Oh. Sorry. I thought you were someone else."

-- Carrot travels to Ankh-Morpork (Terry Pratchett, Guards! Guards!)

He nodded to the troll which was employed by the Drum as a splatter [footnote: Like a bouncer, but trolls use more force].

-- Nobby takes Carrot for a drink in The Mended Drum (Terry Pratchett, Guards! Guards!)

It was possibly the most circumspect advance in the history of military manoeuvres, right down at the bottom end of the scale that things like the Charge of the Light Brigade are at the top of.

-- The City Watch takes action (Terry Pratchett, Guards! Guards!)

Lady Ramkin's bosom rose and fell like an empire.

-- (Terry Pratchett, Guards! Guards!)

It's a metaphor of human bloody existence, a dragon. And if that wasn't bad enough, it's also a bloody great hot flying thing.

-- Captain Vimes ponders his problems (Terry Pratchett, Guards! Guards!)

The three rules of the Librarians of Time and Space are: 1) Silence; 2) Books must be returned no later than the date last shown; and 3) Do not interfere with the nature of causality.

-- (Terry Pratchett, Guards! Guards!)

A number of religions in Ankh-Morpork still practiced human sacrifice, except that they didn't really need to practice any more because they had got so good at it.

-- (Terry Pratchett, Guards! Guards!)

Thunder rolled. ... It rolled a six.

-- (Terry Pratchett, Guards! Guards!)

"Right, you bastards, you're... you're geography"

-- (Terry Pratchett, Guards! Guards!)

"The significant owl hoots in the night."

-- (Terry Pratchett, Guards! Guards!)