Colon and the boys' numbered list of reasons for expanding the barricades to include a quarter of the city while "Keel" is away. Fred's "Are you okay, Sarge?" and subsequent apology after the implied Face Palm being included as the final items on the list always raises a chuckle.
The destruction of Big Mary (a large siege weapon) with a couple of wooden wedges and some lumps of raw ginger.
And young!Vimes' subsequent reaction, staring at "Keel" with wide eyed hero worship.
Detritus' training song for the new recruits:
Now we sing dis stupid song Sing it as we run along Why we sing dis we don't know We can't make the words rhyme prop'ly Sound off! One, two! Sound off! Many, lots! Sound off! Er, what?
"Yeah? On whose authority?" Vimes swung his crossbow up. "Mr Burleigh and Mr Stronginthearm," he said, and grinned. The two guards exchanged glances. "Who the hell are they?" said one. There was a moment of silence followed by Vimes saying, out of the corner of his mouth: "Lance-Constable Vimes?" "Yessir?" "What make are these crossbows?" "Er... Hines Brothers, sir. They're Mark Threes." "Not Burleigh and Stronginthearm?" "Never heard of them, sir." Damn. Five years too early, thought Vimes. And it was such a good line, too.
He finally goes with "You will let me take these prisoners or I will shoot you in the face." Not snappy, but it does get the point across.
"I repeat, I order you to dismantle this barricade." He took a deep breath and went on. "And rebuild it on the other side of the corner with Cable Street! And put up another one at the top of Sheer Street! Properly built! Good grief, you don't just pile stuff up, for god's sake! A barricade is something you construct!"
Made all the funnier that in the rush to construct the barricade, some of the furniture they use includes a chair with an old man still sleeping in it.
Also this hilarious bit of snark from Vimes when confronted by said old man's uptight daughter:
Venturi and Selachii at the party — as Arch Enemies they agree on nothing, but etiquette demands that they are polite to one another and, at least at social gatherings, talk without getting into an argument. They solve this by only talking about things it's completely impossible for even them to disagree about:
Selachii: This is a party. Venturi: Indeed. I see you are standing upright. Selachii: Indeed. So are you, I see. Venturi: Indeed. Indeed. On that subject, I notice many others are doing the same thing. Selachii: Which is not to say that the horizontal position does not have its merits when it comes to, for example, sleeping. Venturi: Quite so. Obviously that would not be done here. Selachii: Oh, indeed. Indeed.
Not to mention Knock's growing panic as he realizes his plan has gone completely pear-shaped.
Knock: Is there a loose panel, or something?
Coates: What, in a sack, Sarge?
Death to Lord Winder: You have reached the end of cake.
The creation of the People's Republic of Treacle Mine Road includes a rather unique rally cry: 'Truth! Justice! Freedom! Reasonably priced love! And a hard boiled egg!'
For context; Reg Shoe has been trying to establish the laws of the new Republic, and has been arguing with the Seamstresses about the aforementioned 'reasonably priced love': "Free is not a word we wish to hear." Then Vimes (as Keel) shows up:
Reg Shoe: You'd like Freedom, Truth, and Justice, wouldn't you, Comrade Sergeant?
Vimes: I'd like a hard-boiled egg.
Reg Shoe: In the circumstances, Sergeant, I think we should set our sights a little higher—
Vimes: Well, yes, we could,[...] But...well, Reg, tomorrow the sun will come up again, and I'm pretty sure that whatever happens we won't have found Freedom, and there won't be a whole lot of Justice, and I'm damn sure we won't have found Truth. But it's just possible that I might get a hard-boiled egg.
And, as something of a Brick Joke, later on when they're on the barricade, Sandra Battye brings him a boiled egg, with some toast cut into little soldiers...
...which quickly gets destroyed as the enemy starts attacking out of nowhere. Vimes promptly punches the first man up over the barricade: "That was my egg, you bastard! With soldiers!"
Many of the soldiers sent against the barricade come from the very neighborhoods behind the barricade. This makes their job more difficult, as their grandmothers are up on the barricade, threatening to tell everyone about what they did when they were eleven...
You Do Not Drop Your Mates In The Cacky. Full stop.
Vimes' reactions to encountering Nobby Nobbs (as a Gavroche expy) and Lord Rust.
Vimes is talking to Captain Swing of the Unmentionables, who comments that the former is "a man after his own heart". Vimes "takes a moment to consider the anatomical possibilities" before replying:
The moment when Ridcully lands in front of the Watch naked. Because taking off his ownpointy hat would be unthinkable, he makes Ponder give him his hat to cover up. Also, "We've never seen so much of a wizard before, sir."
A well-timed bit of levity in an otherwise extremely dark part of the book, as Vimes ponders on the inhumanity of man:
Vimes' Inner Monologue: Who knew what evil lurked in the hearts of men?
Young Nobbs describing how he met Vetinari's aunt for the first time: He tried to pinch the wheels of her cart. In response, she picked him up and punched his lights out (according to Nobby's recollection, she hit like a mule - that is to say, really hard). When he came to, she offered him a job.
As the Treacle Mine Road Watchmen are being chased by Carcer towards the end of the book, young Nobby catches up with Vimes to deliver some important information.
The Garden of Inner-City Tranquility - in which each item gets an appropriately mystical-sounding explanation from Lu-Tze, except for the beer bottle, which some asshole keeps tossing in there on Friday nights.
Lu-Tze: If it wasn't forbidden to do that kind of thing, he'd feel the flat of my hand and no mistake.
In The Sixth Watch, the Running Gag of Gesar and Zabulon's bet over whether the Gorodetskys would panic upon hearing about the prophecy. They don't, and Gesar triumphantly takes Merlin's tobacco pipe from a sullen Zabulon. Later, when the family ditches the Great Ones and makes their exit via portal Anton hears Gesar tell Zabulon, "I told you, Dark One! Merlin's tobacco pouch if you please!"
Even funnier is that the tobacco is absolutely disgusting to smoke but Gesar stubbornly keeps smoking it to make a point.
Also in The Sixth Watch, fourteen year old Nadya freaks her parents out by casually implying she and Kesha had sex... before revealing they just made a Blood Brothers pact. Svetlana and Anton are understandably not amused.
Followed by them relentlessly trolling her by claiming they're going to give her and Kesha The Talk.
Gesar and Zabulon's bickering, which doesn't relent even when the end of the world is nigh.
Zabulon is Anton's grandfather. Just think about all their interactions in light of that revelation. Becomes a /Heartwarming Moments when you remember all the references to Zabulon's perceived 'fondness' for Anton.
Svetlana slaps Gesar, Great One and most powerful Light One in all of Russia, across the face. He is stunned. And then she does it again on Anton's request that she gives him one on Anton's behalf.
Svetlana: I've been dreaming about doing that for a long time!
The Tiger, all-power being and embodiment of the Twilight, has taken up smoking and drinking coffee... after watching Anton. He's also developed a sense of humour.
The film version of Night Watch adds some humor to the scene where Anton first sees the physical manifestation of Svetlana's curse while trying to track down a vampire in the subway. The audience is seeing things from his perspective and knows that his glasses and flashlight are vampire tracking equipment... But once Svetlana exits the subway car, the special effects abruptly stop and we see what the other passengers were seeing this whole time: Some idiot wearing sunglasses indoors, screaming and freaking out while waving a flashlight around at nothing. To bring it home, the woman standing next to him scoffs and says he must be on drugs.