The pirates sing a merry song about how they are going to Rape, Pillage, and Burn the fort to hell and back, but most are just getting drunk and having fun.
A seagull has made a nest out of a skeleton's hat, which is still on its head.
The bar scene with the drinking skeletons. Two are sitting at a table, posed like they are having a casual drink while covered in cobwebs. The third "drinks" a bottle, with the contents trickling through his ribcage.
The crowned skeleton most now know as Ponce de Leon sitting in a large bed reading a treasure map.
The pirates dunking the town's mayor over and over again in the well to make him talk. Every now and again, the mayor's wife, a real Grande Dame, bursts out of a window above to scold her husband (who is tied up and soaking wet). One of the pirates shuts her up by firing a gun at the window, only for her to appear again.
"Mr. Cotton! Do you have the courage and fortitude to follow orders and stay true in the face of danger and almost certain death?!"
Jack: Do you have the courage and fortitude to follow orders and stay...I love you man, let's just face the fact.
Jack: Do you have the courage to fortitude...
Jack: Do you have the courage and fortitude to follow orders and stay brave in the sea...oh, god, I hate this bloody line. Where are the writers? I'm gonna kill them...
Not to mention, he said all of that last bit in character.
On the deck after rescuing Elizabeth, Norrington is mocking Jack's equipment and then suddenly...
Johnny Depp: Was that a plane?
At one point, Elizabeth appears to spontaneously explode.
At the Pirate Council:
Johnny Depp: "Let us not, dear friends, forget our... lines. Yes! Let us not forget our lines."
Johnny Depp forgetting the name of the Flying Dutchman and calling it The Davy Jones Crocodile Machine.
There's also Orlando Bloom's "Aarrrr, swash swash, buckle buckle," and Tom Hollander and Johnny Depp's numerous tries to get a scene done (the bargain upon the Endeavour), which includes Hollander's haughty "I'm trying to work here," and Depp's "That be...You can't curse on a Disney film, mate. *pause in which the director confirms* ...see, I told you!"
Context for the repeated failed shots: Hollander and Depp are filming the scene with a foghorn outside. It's so loud and close by that when it goes off, it nearly knocks both of them off their feet. Of course, this happens more than once...
Actually, the scene is where a cannonball bursts through the room right before they shake hands to close the deal. The foghorn was there as a way for them to know when to act out being surprised of the explosion. They know it's coming so they have to simulate a realistic reaction if cannon ordnance suddenly bursts through right next to you. Being 'nearly knocked off your feet' is an understandable reaction to an explosion. Still, it is surprising so their reactions are more forced since it's not a cannonball but a very loud horn, simulating the force a cannonball would project when exploding nearby will need to be forced.
Hollander doing an impromptu jig while filming a scene.
One take of the otherwise dramatic opening scene in Dead Man's Chest:
(Governor Swann) "The charge is conspiring to set free a man convicted of...*takes a sigh with a long pause* ...I can't read my own writing. Crimes! Thank you very much!" (If you look closely, you can also see Tom Hollander (Beckett) struggling not to crack up.)
This one ties into Governor Swann's above quote:
Beckett: The charges are conspiring to set free a man legally... lawfully... Sorry, I'm slightly confused because I didn't know which verse we were doing. Shall I say it or Jonathan (Governor Swann) say it?"
Governor Swann: It's my line, dear.
Governor Swann: It's all right. (Jokingly mimes while shaking his fist at Beckett as if he wants to punch his face.)
Jack's conditions of help: "I shall help you to find the compass, if you'll do strange things to my dog. His name is Tim."
Geoffrey Rush staying in character when he flubs his lines:
"Calypso! I come before you as but a servant... *his hat is blown off* Ye blew my hat off, ye *bleep*!"
"And I won't let the likes of Beckett Cutler... *pause* er, sometimes known as Cutler Beckett..."
Will: *yells an order to the crew.* Barbossa: "NAY BELAY THAT!" *long beat* "...DO SOMETHING ELSE!"
Geoffrey Rush accidentally hitting himself in the eye with his spyglass is known to cause giggles and sympathetic wincing at the same time.
In another outtake, Depp is shooting the Locker scene where he swings from the Pearl onto the desert below. He preps, swings, the camera follows, and crash; Depp crashes onto the ground, having mistimed his landing.
Johnny Depp: *under his breath* "Oh, my god..." *gets right to his feet completely in-character*
During the Parlay scene from At World's End, as Geoffrey Rush, Keira Knightley, and Johnny Depp are walking, Rush's hat flies off due to the wind. What does Depp do? Staying perfectly in the character of Jack Sparrow, he tosses his own hat off and strikes a dramatic pose.
Jack's incident with the Jar of Dirt.
Jack: Why fight when you can negotiate? [Begins to remove Jar of Dirt from his pocket.] All one needs — [realizes his wig is caught in the jar while Will laughs] Help?
Helicopters keep interrupting during On Stranger Tides
Johnny: What I want first...is Ponce de Leon's helicopter.
Scrum: ...or when an helicopter flies over your head, and you're supposed to be in the middle of a scene. It's not real.
Extra: It screws everything.
"I'm Peter Pan!"
Even funnier if you've played Kingdom Hearts 2. Due to the lack of a Neverland level in that game, Sora gets the Peter Pan/Tinkerbell summon in Port Royal instead.
Johnny's numerous attempts to get the hat off Penelope's head.
Johnny: I think this take's going very well, don't you?
Rush attempting to get his wooden leg back on.
Rush: No, it's broken.
Depp: Can't help you, mate. I don't want to touch it.
The best part: both say this in character.
"God, stop it, please!"
Made funnier by the fact that Philip is a man of the cloth; this line works in and out of character.
On Stranger Tides: Johnny appears from round the corner...with his hat on wonky. He notices, straightens it before backing out of the scene.
Deleted Scene from AWE. Barbossa and Jack are fighting (like children) over who gets to steer the ship. They even go so far as to wrestle over the wheel. Even more so when it's revealed that they've split captaincy of the ship between them...by sides.
In another At World's End scene, Jack and Beckett having a discussion, during which Beckett pours them both a drink... only for Jack to take both glasses. When Beckett pours himself another glass, Jack grabs it as well. At the end, Beckett goes to pour himself a third drink... only to pause when Jack is poised to snatch it again.