- Stu's "Tiger Song". Also, the fact that Ed Helms improvised his singing and piano playing skills.
- 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:
Melissa: 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! (Beat.) 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.
- In one of the outtakes, former heavyweight boxing champ Mike Tyson is being told how to fight (on camera) by director Todd Phillips, and jokingly responds 'Oh great, I'm being told how to fight from the captain of the Jewish debating team!
The Hangover Part II
- Stu singing "Alantown".
- Stu's reaction when he realizes that he had sex with a transsexual, and he was the "bottom".
- Some of Chow's quotes:
Phil: What business is that?Mr. Chow: It's called not your business, 'kay?
- "I have such an erection right now!" Chow says this after the high speed car chase and crash.
- Chow mentions his business with Kingsley.
- "Your password is baloney1?" "It used to just be baloney, but then they make you put numbuuhhh."
- "You never do blow before? Sometimes your heart stops, start up again. Read a book!"
- Alan's joke in the back of the truck manages to make everyone else—including the silent monk—laugh their asses off.
Alan: When a monkey nibbles on a penis, it's funny in any language.
- Stu's "bachelor party."
Stu: You see that? That's orange juice with a napkin over it... so nobody Roofie's me!
- Stu's reaction after one too many people say "Bangkok has him now":
"Why does everyone keep saying that?!"
- Alan's interactions with the monkey.
- Phil's entirely justified reaction to Alan messing around with an Uzi and accidentally spraying half the clip into the ceiling.
Phil: ALAN, WHAT THE FUCK?!?!
- The video of the guys starting a riot outside the tattoo parlor and Stu yelling "Fuck the po-lice!"
- The monk kicking the guys' asses for talking in a meditation chamber.
Phil: Maybe put up a "No Talking!" sign, instead of sicking Crouching Tiger here on us.
- Phil's reaction later to the said ass kicking.
- At the end, the completely offhand way Stu explains to Teddy where his finger went.
Stu: We gave it to a drug-dealing monkey.[beat]Teddy: Bangkok.Stu: Yup, Bangkok.
- When the guys are arriving at the wedding, Doug blinks and says "Is that Alan driving?" Then he and his wife make sure everyone gets out of the way.
Stu: I'm sorry we almost killed everyone...
- Mike Tyson.
- Alan's meditation moment where he tries to remember what happened the night before, only he imagines him, Phil, Stu, Doug, and Chow as kids.
The Hangover Part III
- 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!"
Stu: Just tell me, is it the one to the left, or the right?Chow: Which is which again? I'm also dyslexic.Stu: What. The. Fuck?!
- 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. You can practically hear the "You have got to be kidding me!" in Stu's voice after the second revelation.
- 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: Exactly! (Marshall tears up that note and reads another one)Marshall: "Dear Alan, I threw urine on prison guard this morning, blamed it on cellmate. Wish you were here."Alan: Yeah, I wish I could have seen that!
- 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".