- Mike Tyson trying to sing "In The Air Tonight".
(upon watching the security feed at Tyson's place)
Tyson: Where'd you get the cop car?
Stu: We, uh, stole it from these dumbass cops.
Tyson: (grinning from ear-to-ear) NICE!
- The Wolfpack. I'll say no more.
- "[Rain Man] was a ri-tard." "REE-tard."
- "That's a good idea, Dr. Faggot."
- Mr Chow pops out of the car boot, naked, attacking the main characters.
- Alan: "I didn't know they gave out rings during the Holocaust."
- Mr. Chow: "It's funny because he's fat."
- Alan's loner speech.
- The Rain Man Shout-Out, especially Alan perfectly mimicking Dustin Hoffman's affectations down the escalator.
- "Our best friend Doug is probably face-down in a ditch right now with a meth head butt-fucking his corpse!"
- Alan's response to the legality of counting cards while gambling.
Alan: Gambling? Who said anything about gambling? It's not gambling when you know you're gonna win. Counting cards is a foolproof system.
Stu: It's also illegal.
Alan: It's not illegal. It's frowned upon, like masturbating on an airplane.
Phil: I'm pretty sure that's illegal too.
Alan: Yeah, maybe after 9/11, where everybody got so sensitive. Thanks a lot, bin Laden.
- Alan trying to calm an enraged Mr. Chow.
Mr. Chow: You gonna fuck on me?
Alan: Nobody's going to fuck on you! I'm on your side! I hate Godzilla! I hate him too! He destroys cities! Please! This isn't your fault. I'll get you some pants.
- Alan interacting with the hotel staff.
Alan Garner: Can I ask you another question?
Alan Garner: You probably get this a lot. This isn't the real Caesar's Palace, is it?
Lisa: What do you mean?
Alan Garner: Did, umm... did Caesar live here?
Alan Garner: I didn't think so.
- The cops barging in on Jade's room. "Shut the baby up! Shut the baby up!"
- The tiger in the back seat waking up.
- This exchange:
I just wish your friends were as mature as you. Stu:
They are mature, actually. You just have to get to know them.
(Phil, Doug and Alan pull up outside.) Phil:
Paging Dr. Faggot
- The entirety of the taser demonstration, but the little girl shooting Phil in the crotch takes the cake.
- Chow taunting the Wolfpack after giving them the wrong Doug:
Chow: Oh, I'll give your money back, right after you suck on these little Chinese nuts! (makes jerking off motion/sound effect) So long, gayboys!
- The photos on the camera during the credits are arguably the funniest part of the movie. Notable highlights include:
- Alan fiddling with his pager as a lapdancer attempts to perform for him.
- Stu drinking heavily from a bottle of whiskey...
- ... and then vomiting copiously in the very next shot.
- Stu pulling out his own tooth.
- Mr Chow cuddlng and kissing Allen as he gambles, and then Alan asleep on the table.
- Alan getting his belly button pierced.
- Alan falling in a fountain.
- The whole group's antics with Mike Tyson, including taking photos of him in bed and straddling his pet tiger.
- Alan singing "Ave Maria" in a high operatic voice.
- Also this:
Alan: My name's Alan and I bought a giraffe! My life is great!
- Phil, dangling off the side of Caesar's Palace on a towel rope, only for Alan to ask him to kick out from the building for a photo op. Topped off with Phil genuinely asking if Alan got the shot.
- Chow and Stu crawling on all fours to get into Chow's villa, complete with Chow sniffing Stu's ass and trying to eat dog food, and then crying "OH MY GOD, SO GROSS!"
- When they're trying to disarm the villa's security system by cutting the same in two panels at the same time, only for Chow to be unable to tell Stu which one due to being color blind.
Stu: Just tell me, is it the one to the left, or the right?
Chow: Which is which again? I'm also dyslexic.
- This exchange:
Marshall: "You introduced a virus into my life."
Phil: "Oh, God. What did he do?"
Marshall: "He fucked me in the ass."
Alan: "Oh, he does that from time to time."
Marshall: "Not literally!"
- The Stinger. The morning after Alan and Cassie's wedding, a hotel room is shown to be completely trashed (think of the other morning-aftermath scenes from the other movies), with a motorcycle stuck in a wall along with a minigun having shot many holes in another wall, Phil waking up in Cassie's wedding dress and Stu walking in to the room, with breast implants! (But Stu only notices that he's wearing women's panties.) The Freak Out that follows when he notices his new boobs is also insanely funny. And the gangs Oh Crap! reaction when Alan remembers that Chow gave them the wedding cake, cutting to the same monkey from the second Hangover film jumping on his head, and Chow popping up, totally naked with a samurai sword.
- Marshall reading Alan and Chow's letters to each other.
Marshall: "Dear Leslie, OMG, the McRib is back! Why was it ever gone?"
Alan: I know, right?
Marshall: "Dear Alan. Today I peed on a guard and blamed it on another inmate. Wish you were here."
Alan: Yeah, I wish I was there too. It sounds hilarious.
- The entire scene scene with the chickens attacking everyone and Chow trying to shoot them, then Chow reveals that he only feeds them cocaine and chicken.
- The guys repeatedly calling the other Doug "Black Doug" and him getting increasingly irritated by it.
- Chow singing karaoke.
Phil: What the fuck am I watching?
- Alan's phone password is "Hey Phil".