In the iconic scene where everyone sees their first live dinosaur, Ellie is very preoccupied with the leaf of an extinct plant she picked up. Finally, Grant grabs her head and physically makes her look. Cue dropped jaw...
The robot arm in the dinosaur nursery taking the hatched egg right out of Grant's hand and setting it back down. The look on his face...
This gem from early on, after Malcolm, Sattler, and Grant all argue against Jurassic Park:
Hammond: I don't believe it! Hah! I don't believe it! You're supposed to come here and defend me against these characters and the only one I've got on my side is the bloodsucking lawyer!
Gennaro: Thank you.
Later, when the dinosaur tour falls flat thanks to the non-appearance of the dinosaurs:
Malcolm: Ah, now eventually you do plan to have dinosaurs on your, on your dinosaur tour, right? Hello? (taps the camera lens, breathes on it) Hello? Yes?
Hammond: (deadpan) I really hate that man.
This famous exchange, but especially right after with Ian and Alan turning to stare at her, and Alan's little smile:
Ian: God creates dinosaurs. God destroys dinosaurs. God creates man. Man destroys god. Man creates dinosaurs.
Ellie: Dinosaurs... eat man. Woman inherits the earth.
Ian's utterly deadpan reaction to the Triceratops feces:
"That is one big pile of shit."
Gennaro bolts upon seeing the T. rex and hides in a toilet cubicle. Alan and Ian see this, but not the T. rex.
Alan: Where does he think he's going?
Ian: When you gotta go, you gotta go.
After Grant retrieves Tim from a car stuck in a tree, the branches snap and the car comes loose, crashing down through the tree and landing on top of them (luckily the roof was missing, creating a safe spot), and then...
Tim: Well...we're back...in the car again.
Grant: At least you're out of the tree.
Later, everyone has to climb a tree to stay safe for the night. Tim objects.
When the Tyrannosaurus is chasing a Jeep and it appears in the "Objects in mirror are closer than they appear" mirror. As if it could be any closer already.
After learning that all the dinosaurs are female.
Ian: So how do we know? Does someone go out into the park and pull up the dinosaur's skirts?
When the the dinosaurs start rampaging, the protagonists are unable call for help or evacuate because all the phones are down. (courtesy of Nedry's virus.) When they finally reestablish communication, Grant informs Hammond via phone... who fails to comprehend that they can finally leave the island.
Nick Van Owen: (awkwardly, gesturing between the reunited father and daughter) Do you see any family resemblance here?
When the Tyrannosaurus is rampaging through San Diego: while chasing Malcolm and Harding in their car, San Diego police and Animal Control show up. They have just enough time to get one good look at the T. rex before it roars and they throw their cars into reverse.
Also in that sequence, Ian and Sarah are trying to get the T. rex's attention so they can lead it back to the boat.
Ian: It's never gonna know we have it unless that thing makes some kind of sound!
Sarah:(the T. rex looks over in their direction) He knows.
(*CRASH* The 76 ball off of the nearby gas station rolls past their car)
Later, as the T. rex is chasing them, Sarah suggests that Ian should slow down so they don't get too far ahead of the T. rex and lose its attention. Ian takes one glance behind them to see how close the T. rex is and promptly hits the gas harder.
Also from the T. rex's rampage we have a man doing a Godzilla Shout-Out saying "I left Japan to get away from this" in Japanese.
During the scene where the T. rex bites the traffic signal, sharp-eyed viewers will notice that the street sign on the right reads "No Skateboards, No Dinosaurs".
Malcolm asks Nick why he joined Greenpeace. His answer: Women. Malcolm's response: "Noble, very noble."
When they first get to the island, they go into the jungle and find Sarah's backpack. Ian starts shouting, "Sarah!" and Nick yells, "Sarah Harding!" Ian stops, gives him a look, and asks, "How many Sarahs you think there are on this island?" Gets a call back later — when they're searching for Nick, most of the group is just yelling "Nick!" while Ian absentminded chimes in with, "Nick Van Owen!"
Roland Tembo has quite a bit of trouble with the pronunciation of the dinosaurs' names.
And later it seems like his team is having fun with his explanations:
Hunter: Say again, Roland, a what?
Tembo: The one with the big red horn. Pompadour. Elvis!
When the group, looking for Sarah, finally sees their first dinosaur and naturally, Eddie and Nick are slack-jawed while Ian is unimpressed. Ian asks them why they're so shocked and Nick tries to explain that he didn't really think he'd see actual dinosaurs.
Malcolm: What did you think you were gonna see?
Nick: Animals. Maybe, uh, b-big iguanas.
Malcolm: (shakes his head) Fruitcake.
The crown jewel, in this troper's opinion, is when Nick, Sarah, and Malcolm are dangling perilously in the trailer about to fall off a cliff and still have time to be sarcastic.
Eddie: (yells down to them) What do you need?
Eddie: Rope! What, anything else?
Malcolm: Yeah! Three cheeseburgers with everything on 'em.
Nick: No onions on mine!
Sarah: And an apple turnover!
During the T. rex rampage scene, it comes upon the backyard area and starts slurping up the water of a pool. A dog comes and starts barking it but quickly goes back into it's doghouse when the T. rex growls at it. This is followed by a child waking up and seeing it, then going to his parent's bedrooms to tell them. They don't believe him at first, thinking it a usual childhood fear of the dark and eventually go to the bedroom to reassure him there's nothing wrong...until they look out the window and see a T. rex right in of them with the chain of the dog danging from it's mouth along with the doghouse. The parents promptly scream, the child...takes a picture of it.
When Burke describes the way Pachycephalosaur's skull is extra thick on the top of its head and is purposefully designed for absorbing impact. A second later, the Pachycephalosaurus helpfully demonstrates this point by ramming its head into a car door with enough force to send the two men inside the car crashing out of the windows on the opposite side.
Ian gets a golden Brick Joke line, after his daughter uses a complicated uneven-bars gymnastics routine to kick a Velociraptor out the window.
Ian: [incredulously] The school cut you from the team?
Jurassic Park III
During a moment's reprieve in an abandoned laboratory, the group stops by some vending machines. Mr. Kirby takes out some money, but finds he's got no singles
Mr. Kirby: Uh....anybody got change? I got a....ten...
(Billy proceeds to kick through the glass of a nearby machine and takes out some snacks. Mr. Kirby attempts the same on his machine and succeeds only in spraining his own ankle.)
In the scene where Grant and the others are digging through the Spinosaur's crap for the phone that won't stop ringing, we get a nifty little cameo from a Ceratosaurus, which is a miniature T. rex with a horn on it's snout and for a moment we think the group is in trouble. It sniffs them out (all of 'em covered in crap) and it rears its head back (looking to the audience) in disgust and excuses itself from the area. Oh hai, Ceratosaurus; oh...bye, Ceratosaurus.
During the scene on the river when Grant is calling Ellie for help. Her son picks up the phone:
Grant: (in dire plea for help) Charlie, take the phone to mommy! It's the dinosaur man!
And in the midst of taking said phone to his mother, the kid catches Barney on the television screen and proceeds to watch it for a few seconds whilst hopping up and down until he realizes "oh yeah, Dinosaur man needs my help".