The Rain Man shout out, especially Alan perfectly mimicking Dustin Hoffman's affectations down the escalator.
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? Lisa: Sure. 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? Lisa: No. Alan Garner: I didn't think so.
The cops barging in on Jade's room. "Shut the baby up! Shut the baby up!"
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.
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:
"I have such an erection right now!" Chow says this after the high speed car chase and crash.
Chow mentions his business with Kingsley.
Phil: What business is that?
Mr. Chow: It's called not your business, 'kay?
"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.
Hell, the monkey itself is a walking CMOF — when this troper saw the movie, it got a laugh in every scene it was in.
The monk kicking the guys' asses for talking in a meditation chamber.
Phil's reaction later to the said ass kicking.
Phil: Maybe put up a "No Talking!" sign, instead of sicking Crouching Tiger here on us.
At the end, the completely offhand way Stu explains to Teddy where his finger went.
Stu: We gave it to a drug-dealing monkey.
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...
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.
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.