When Jed and Octavius are popping Cecil's tires, and they get blown away by the violent gush of air coming out of the vent. Made funnier when the scene cuts to a Distant Reaction Shot of the van from a normal person's perspective that shows an almost inaudible sound being made as the air is released.
Atilla portrayed as a huge fussy child with anger problems equals comedy gold. The scene were Larry manages to connect with him and the Huns is both funny and heartwarming.
Dr. McPhee in general, but especially when Larry has to explain himself the next morning for humorous positions that the miniatures froze in:
McPhee: Whahahahaha. Let's all laugh at me, the comedy night guard. No, is the answer. Sarcasm, back at you, with your humor box. I wasn't laughing. I was pretending to laugh, if that's what you want, some sort of battle of humor. Do you? Larry: No? I don't want a— No, I don't want a battle of humor. McPhee: No, you don't, because it would be a bloodbath. Nothing funny about Little Bighorn. No. I find it about as funny as a fancist... It's not funny. Okay? And I will not stand for this type of blatant ssss.... If I'm not clear, tell me. (Beat) Am I clear? Larry: Yeah? McPhee: Yeah.
Or this bit when he reluctantly decides to give Larry one last chance:
McPhee: And if anything, the tiniest... after your shift... (smacks his hands together and makes a smashing sound effect) Because... Larry: Got it. McPhee: Okay. Fool me once, shame on you. Fool me twice... Larry: Shame on- McPhee: Huh? Larry: Fool me... Shame on me.
The one-scene wonder with the whale squirting water out of its blowhole at the head night guard.
Teddy: Good Lord, Lawrence, why are you slapping a monkey!?
Even better, Larry's response, and the way he says it.
Larry: Teddy, this guy has been pushing me and pushing me, and I am sick of it!
Teddy's response to Larry accusing him of spending years on spying on a girl he's never even talked to. (Sacajawea.)
Teddy: (defensively) I was about to make contact.
Battle of the Smithsonian
Kahmunrah's dismissal of Darth Vader as an incompetent villain because he's an "asthmatic in an opera cape".
Kahmunrah: Can I make one suggestion to you my friend? Just simplify. There's just too much going on here. You're evil, you're asthmatic, you're a robot, and what is-what is the cape for? Are we going to the opera? I don't think so.
Also, the moment when Kahmunrah kidnaps Jedediah.
Kahmunrah: (to Jedediah) I'm sorry, but I can't take you seriously, even when you're threatening me! You're just adorable!
Plus the Overly Long Gag where Larry and Kahmunrah try to negotiate over Larry's friends and the tablet. A highlight:
Larry asking Octavius to stop looking off into the middle-distance when he speaks in a melodramatic manner.
When Abraham Lincoln shows up and curbstomps Kahmunrah's Army of the Dead:
Jed: Adios, bird-brains! Lincoln: Good-bye, strange bird men. Kahmunrah: Do not return to the underworld! Octavius: Yes, yes, do go back into the underworld. Thank you for coming! Good night! (the Army of the Dead closes the door behind them) (Beat) Kahmunrah: Well...this is awkward.
Octavius attempting to get help from the President in order to save his friends. In the same vein as the tire scene from the first movie, he sprints across the White House's yard while holding his sword up high and yelling a mighty battle cry...and then it cuts to the White House looking completely ordinary, and then it cuts back to the close up of Octavius running dramatically.
Secret of the Tomb
The fact that the Museum Director had a caveman added to the exhibit that looks just like Larry as a joke.
When Teddy Roosevelt first meets Lancelot
Lancelot: Sir Lancelot, at your service. Teddy Roosevelt: Theodore Roosevelt: President of the United States of America. Lancelot [cheerfully]: I have no idea what that means.
First off, the entire planetarium disaster. Attila attacks an ice sculpture of a dolphin, Teddy goes nuts, Dexter attempts to impale Dr. Phelps with a kebab and all the animals decide to stampede, while Jed and Octavius trip people over.
Before that, Jedediah and Octavius watch a cat video. What happens next is hilarious.
Octavius: I should like to comment! Summon the apparatus!
Sentry: SUMMON THE APPARATUS!
*Apparatus rolls up.*
*L key is hit with an ice cream stick.*
*O gets hit as well.*
*L key gets hit again.*
Octavius: Add a smiley and a wink!
Sentry: ADD A SMILEY AND A WINK!
Octavius: Now submit this video and my edict of approval to Facebook!
Lancelot cheerfully noting that Larry pretty much looks exactly like his jester, Eric. Who stood there with a deadpan expression and made everyone laugh.
He then proceeds to call Larry Dangly Bells for a good chunk of the movie.
Merenkahre: I love Jews! We owned over 40,000 of them.
Shepseheret: Such lovely people!
Akhmenrah: Here we go...
Merenkahre: They were very happy, always singing, with the candles...
Larry: Yeah, they really weren't happy...
Larry: No, they left. They spent about 40 years in the desert trying to escape.
Larry: Yeah, we have dinner once a year and talk about it. It's a...big deal.
Near the end, when the tablet is back to normal and Lancelot has decided to remain a good guy:
Merenkahre: You have served my family well. We will bury you in a great tomb with many riches, and I will personally see to it that your organs are removed and placed in several jewel-encrusted jars!
Which actually, if you know about Egyptian burial rites, is a promise of great honors for Larry in death.
Lancelot invading a staging of Camelot. And Hugh Jackman's and Alice Eve's performance.
Upon seeing the theater:
What have they done to Camelot?!
Jackman does the Wolverine Claws motion (complete with the X-Men theme playing in the background)... and Lancelot doesn't get it, of course.
"STOP LOOKING AT MY NOSE!!!"
Everything that Laa does, really. For example, deciding whether or not to fulfill his duty as a makeshift night guard or eat the packing peanuts.
The Dance Party at the end.
Distracting the Lions at Nelson's Column. Larry just waves his flashlight and the Lions go nuts.
The entire Pompeii sequence:
First, just as Octavius and Jed land in the miniature city, they notice all the miniature Roman citizens running away and a male bust repeatedly shouting a single name repeatedly. Octavius then bends down to read the name of the exhibit:
Octavius: Iiepmop. Hmmm...doesn't ring a bell.
The bust using his tongue to point to the volcano.
And when they see the volcano erupting:
Octavius: Oh. Pompeii.
*Cut the two of them running away from the lava screaming.*
Tilly's entire romance with Laa is pretty much a parody of every romance cliche, ever.
"I'M ALREADY MAKING SKETCHES OF YOU IN MY MIND! OK, boy with freckles, fat Asian with hair extensions, evil monkey..."
Jed and Octavius being slammed against a heating grate...by a gentle breeze.
"You'll rue the day you messed with us, you beautiful man!"
Cecil is described by the Librarian (who was playing Candy Crush on her PC earlier) as "the sexiest night guard we ever had." Cue a cut to Cecil dancing with several old ladies.
When the librarian describes Cecil as sexy, she casually adds, "Present company included" to Larry.
Larry talking to Laa about his son Nick. Laa has no idea what Larry's talking about.
Similarly, Nick talks to Lancelot about his crush on Andrea Moreno and how they had Calculus together. Lancelot also has no idea what Nick's talking about, but stands there and listens anyway.
When Larry is having his talk with Laa, Laa points to the locked door trapping them, then indicates to his own head, Larry starts talking about how he really is trapped by his own preconceived notions and how he really wants what's best for his son, while trying to keep an open mind. Meanwhile, Laa meant that he intended to use his head to knock out the glass window on the door. And it works.
As if Laa and Tilly recreating the lift scene from Dirty Dancing (right down to the music) wasn't funny enough, the scene then cuts to the two dinosaur skeletons also performing the lift. With Rexy being lifted.