The Vibrating Luggage conversation. The narrator's insistence that he doesn't have a dildo in his bag is funny enough, but the guy behind the desk's response – a look that screams "whatever you say, pal" – tips it into comedy gold.
After Tyler's introduced, when the Narrator gets off the plane and is looking for a bit of lost luggage, he sees Tyler steal a convertible by hopping in it and driving off with the car's owner chasing after him trying to get him to stop! It might be a bit confusing, since it most likely only took place in the Narrator's mind, but it's damn funny. What makes it funnier is the idea that a random person actually did just leap into a convertible and drive off with it, and the Narrator's mind cut-and-pasted Tyler over it because it's something Tyler would do.
"When the snooty cat and the courageous dog with the celebrity voices meet for the first time in reel 3," the audience gets to see the single frame of porn Tyler spliced in there. Not to mention Tyler's Aside Glance into the camera with a Troll-like smile. And somehow that flash of genitalia was enough to make a little girl in the audience weep.
Tyler:(sweetly) A nice. Big. Cock.
After the Narrator calls Tyler for the first time and meet at Lou's Bar, Tyler consoles the Narrator with this:
Hey man, it could be worse. A woman could cut off your penis and toss it out of the window of a moving car.
Marla's quote after the first time she has sex with Tyler: "I haven't been fucked like that since grade school". Sure, it Crosses the Line Twice, but it's funny as hell. What makes it even funnier is that Helena Bonham Carter actually had no idea how shocking it was – since they don't use the term "grade school" in England, she thought the line was fairly innocuous and was horrified when someone explained it to her later.
The fact that it's somehow worse than the line from the book: "I wanna have your abortion".
Then there's Tyler's reaction to that line.
The behind the scenes story of David Fincher being forced to change the line when the people at Fox told them the original line was too racy. However, they only told him to change it, not tone it down, and because he only agreed to do it once, they couldn't make him change it back.
Even funnier is that David Fincher said he was dying of embarrassment when that scene was shown at the premiere, knowing that Helena Bonham-Carter's mother was in the audience. Fortunately, she apparently thought the scene washilarious.
When the Narrator's boss asks if the blood is the Narrator's.
Some of it, yeah.
"I am Jack's smirking revenge."
The scene near the end with Tyler, the narrator and the van full of nitroglycerin definitely qualifies, even if it's also one hell of a skin-curler.
Tyler: [Narrator fires the gun, putting a hole through the van's rear window, causing Tyler to flail around like mad] WHOA! WHOA!... OKAY! You are now firing a gun at your imaginary friend NEAR 400 GALLONS OFNITROGLYCERIN!!
You've gotta be pretty balls-to-the-wall crazy to have your hallucination call you nuts. It's kinda cool since it shows that the symptoms "Jack's" schizophrenia isn't just the existence of Tyler, it's more realistic than many Hollywood depictions.
A subtler one: when the Narrator shows up at the building near the end, and Tyler's there and tells him that he looks "like a crazy person".
The "nice big cock" reappearing just before the end credits.
Tyler wearing an elbow-length rubber glove after having sex with Marla.
The guy trying to turn away one of the applicants for Project Mayhem can't come up with anything to shout at him, except "And you are too fucking... (Beat)... BLOND!" It's probably the Large Ham delivery.
When Tyler gives out his first "homework assignment" to fight a total stranger, and the members of Fight Club start chasing down random people on the street, with many of them running away.
Especially when one of them tries to goad a priest into fighting him by spraying him and the Bible he's carrying while it lies on the ground with a hose, and it actually works. If you notice, the camera shakes a bit during the priest scene. The cameraman was laughing too hard to hold it steady. And if you look carefully later in the movie, you'll see the priest as a member in the fight club.
Not to mention the car salesmen. When he's pushed to the ground, his shoe goes flying up in the air. That, and his high pitched "Son of a bitch!" sell the scene.
The Narrator's "Break Them by Talking" lecture to his boss, and later on when he beats himself up in his boss' office.
The scene in question had the potential to be extremely unsettling, but having the narrator whistling cheerfully while the security guards escort him out of the building rather undercut that.
"Self improvement is masturbation." Hot damn, Tyler, that is both horribly funny and insightful.
After that, the way "Jack" tries to deny it to Tyler.
"Jack": Why does everyone think I'm you? (Tyler pointedly Looks at him) ("Jack" gives an epic Flat "What" look) Tyler:(Finger snap) Ya got it. "Jack":(Sounding more like "Aw, come on, man" than anything else) Nooooooooo.... Tyler:Say it...?
Just Brad Pitt's delivery when his character has to explain that he's a Split Personality. Like "Really? Do I really have to explain everything to this guy?"
The Narrator takes Marla to a restaurant in order to explain everything and get her out of town. Marla doesn't understand why he gets free food, but takes advantage of it. The Narrator quickly realizes he needs to make a clarification:
Narrator:Clean food, please. Waiter: (Whispering to the Narrator) In that case sir may I advise against the lady eating the clam chowder? Narrator: No clam chowder, thank you.
When the detective first calls the Narrator to talk about the explosion that destroyed his apartment, the Narrator's monotone responses plus Tyler's interruptions lead the detective to chastise the Narrator for not taking the issue seriously enough. In response, the Narrator gives a melodramatic speech about how much the apartment really mattered to him, capping it off with him saying that it was not just the apartment that was destroyed, "It was me!"
The Narrator and Tyler stealing human fat from a liposuction clinic. Starting off, there's Tyler's perfect comedic timing with informing the Narrator on how due to certain substance balance requirements, human fat is the one best suited for soap production, and they're gonna raid a liposuction clinic dumpster; Tyler tossing a full bag into the Narrator's arms awkwardly; and finally when they end up snagging one bag on the barbed wire fence, causing it to tear open and spill the contents, which Tyler fruitlessly tries to catch, only to slip on the fat and fall on his ass.
One of the funniest scenes in the book, that was not used in the film: Marla collects fat from her mother's liposuction and leaves it in the fridge to eventually have work done on her lips. Tyler and the narrator have been sending Marla's mother chocolates, then stealing the collected fat to make soap, which infuriates Marla. They then hide in a broken down car while she destroys the kitchen, ranting that they've "boiled" her mother.
