!!From the book:

* The Marauder's Map insulting Snape:
-->'''Map''': "Mister Moony presents his compliments to Professor Snape, and begs him to keep his abnormally large nose out of other people's business. Mister Prongs agrees with Mister Moony, and would like to add that Professor Snape is an ugly git. Mister Padfoot would like to register his astonishment that an idiot like that ever became a professor. Mister Wormtail bids Professor Snape good day, and advises him to wash his hair, the slimeball."
** Especially since Lupin gets to read it.
*** And especially since he's Moony. Knowing that the normally polite Lupin had the first insult there...
** Harry's reaction, which is basically halfway between breaking down laughing and shitting himself in terror.
** Until we happen upon [[FunnyAneurysmMoment a certain memory of Snape's in Book 5]]...
* There were a few funny little moments in chapter 1, "Owl Post". Among them was the flashback to Ron's attempt to contact Harry via fellytone:
--> '''Ron:''' "HELLO? HELLO? CAN YOU HEAR ME? I- WANT- TO- TALK- TO- HARRY- POTTER!"
--> Ron was yelling so loudly that Uncle Vernon jumped and held the receiver a foot away from his ear, staring at it with an expression of mingled fury and alarm.
--> '''Uncle Vernon:''' WHO IS THIS? WHO ARE YOU?
--> '''Ron:''' "RON- WEASLEY!" Ron bellowed back, as though he and Uncle Vernon were speaking from opposite ends of a football field. "I'M- A- FRIEND- OF- HARRY'S- FROM- SCHOOL-"
--> '''Ron (In a later letter to Harry):''' ''"Happy Birthday, Harry! Look, I'm really sorry about that telephone call... I asked Dad, and he reckons I shouldn't have shouted."''
* [[http://laerry.deviantart.com/art/Boggart-Snape-18214529 Boggart Professor Snape]], in a green dress, with a red handbag, and a stuffed-vulture hat.
** Later on, at Christmas, Dumbledore seemingly gets in a little dig at this when he gets Snape to pull a Christmas Cracker - and out pops a stuffed-vulture hat. Which Dumbledore then cheerfully dons himself.
* Speaking of boggarts, there's also Herminone's taking the form of Professor [=McGonagall=] who told her she failed every subject. Even Ron couldn't stop laughing.
* If there are some readers who think the Quidditch scene's a bit dull, the commentaries of them at least were generally very entertaining. Remember Lee Jordan's opiniated commentary on the particularly brutal Quidditch final?
--> '''Lee''': THIRTY-ZERO! TAKE THAT, YOU DIRTY, CHEATING--\\
'''[=McGonagall=]''': Jordan, if you can't commentate in an unbiased way--!\\
'''Lee''': I'm telling it like it is, professor!\\
...\\
'''Lee'''" [after Malfoy grabs the end of Harry's broomstick to prevent him from catching the snitch] YOU CHEATING SCUM! YOU FILTHY, CHEATING [[CurseCutShort B--]]\\
'''[=McGonagall=]''': [Not even bothering to tell him off, as she was pointing her finger in Malfoy's direction, her hat had fallen off, and she too was shouting furiously.]
** And the mention of Lee swearing so badly into the microphone that [=McGonagall=] tries to take it off of him. Also, his hitting on Angelina Johnson when she gets the Quaffle.
* Floating aunt, anyone?
* After Harry and Hermione help Sirius escape, Snape bursts in, screaming about how he doesn't know how this happened, only that "[[PunctuatedForEmphasis THIS! HAS! SOMETHING! TO DO!]] [[GenreSavvy WITH! POTTER!]]
* Earlier, when Harry gets caught in Hogsmede by Draco Malfoy, who then tells Snape: "What is your head doing in Hogsmeade? Your head is not allowed in Hogsmeade. No part of your body is allowed in Hogsmeade."
* After the disastrous Quidditch match, Harry asks where Oliver Wood is, and Fred replies: "He's still in the showers. We think he's trying to drown himself."
* The "Monster Book of Monsters," especially the comment by the manager of Flourish and Blotts, the Wizard book shop:
--> "I thought we'd seen the worst when we ordered two-hundred copies of "The Invisible Book of Invisibility." Cost a fortune and we never found them!"
* This exchange:
---> Percy held out his hand solemnly as though he and Harry had never met and said "Harry. How nice to see you."
---> "Hello Percy," said Harry, trying not to laugh.
---> "I hope you're well," said Percy pompously, shaking hands. It was rather like being introduced to the mayor.
---> "Very well thanks-"
---> "Harry!" said Fred, elbowing Percy out of the way and bowing deeply. "Simply ''splendid'' to see you old boy-"
---> "Marvellous," said George, pushing Fred aside and seizing Harry's hand in turn. "Absolutely spiffing."
---> Percy scowled.
---> "That's enough now," said Mrs. Weasely.
---> "Mum!" said Fred, as though he'd only just spotted her, and seized her hand too. "How really corking to see you!"
** A couple of pages later... Mr. Weasely says that the Ministry are providing cars to take them to King's Cross and Percy asks why.
---> "It's because of you, Perce," said George seriously. "And there'll be little flags on the bonnets with HB on them-"
---> "For Humungous Bighead," said Fred.
*** It gets even better when you realized the following description "Everyone except Percy and Mrs. Weasley snorted" includes ''Mr. Weasley.''
** Also, Percy going mental at Ron and tearing their rooms apart when Fred and George nick his Head Boy Badge and change it to say 'Bighead Boy.'
* It's all too satisfying to see Malfoy and his crew owned by Harry's Patronus spell when they dress up as dementors and go out into the field trying to scare Harry. It's even more satisfying to see them get owned again by Professor [=McGonagall=] after the match.
* Another [=McGonagall=] moment: "Tripe, Sibyl?" And this:
--> '''[=McGonagall=]''': I hardly think that matters, Sybil, unless there is a mad axeman waiting outside the hall to decapitate the first person to leave.
* "...and Ginny Weasley, blushing furiously, turned up with a get-well card she had made herself, which sang shrilly unless Harry kept it shut under his bowl of fruit."
* When the Gryffindors return to the common room after Ron's been attacked by Sirius Black, Fred immediately says "Excellent, are we carrying on [with the post-game party]?"

!!From the film:

* The UST between Hermione and Ron in ''Prisoner of Azkaban''. The first is during the lecture where Buckbeak is introduced and Hermione, in a panic, grabs Ron's hand. He proceeds to give her this amazed look, and she shoots him a glance that says "Don't you say a word". The second is when they're visiting the Shrieking Shack, and Hermione asks if he wants to get closer. After a short uncomfortable pause, she specifies that she meant closer to the shack.
** The first one gets a Lampshade by the RiffTrax:
--> '''Mike''': "Hermione casts the 'give Ron a boner' spell."
* When Hagrid asks who wants to ride Buckbeak, everyone [[GotVolunteered backs off a step]] making it look like Harry has just volunteered.
* The coda to the floating aunt scene. As Harry stalks off, [[FunnyBackgroundEvent Aunt Marge is visible bobbing and floating off into the distance. Brief, no dialogue, just some distant sound-effects, and it's one of the funniest moments in the films.]]
* Pretty much all of Harry's confusion at going back in time, since Hermione takes her sweet time telling him in the movie, but the best part being right after he sees his past self for the first time.
--> '''Harry''' (two seconds away from freaking out): "This is ''not normal''.
* Dumbledore can make a simple "good night" funny.
--->'''Dumbledore:''' Well?
--->'''Harry:''' [[spoiler:He's free]]. We did it.
--->'''Dumbledore:''' Did what? Good night.
** Bill Corbet: Heh, Grandpa's off his meds again.
* Remember the really annoying RunningGag from earlier in that scene? The elderly man in the portrait who was constantly aroused, and subsequently annoyed by Harry's shining Lumos on the walls and would constantly tell him to "Put out that light"? Well, here's where a RunningGag gets turned into a CrowningMomentOfFunny when Snape, after just being humiliated by the Marauder's Map, his confidence dashed, and being utterly degraded by being proven wrong by a longtime rival, gets his head chewed off by the same portrait of an elderly man in pajamas for shining the Lumos spell right in its face. Snape obeys, but with a look of what could be only TranquilFury on his face.
-->'''Portrait of Old Man: Are you deaf? Put that light out!'''
* Lupin's response to Neville naming Professor Snape as his greatest fear: "Snape. [nodding] Frightens us all."
* Hermione, all pissed off, threatening Malfoy with her wand against a rock wall. She gets to calm down a little and turns her back on him. Malfoy almost immediately recovers his smug look just before she delivers a punch to his face.
-->'''Hermione''': That felt good.
-->'''Ron''': Not good, ''brilliant''.
* In the scene where Hermione is getting the Time Turner ready to use, Harry, curious, reaches out for it. Hermione promptly slaps his hand without looking up from the device, or even breaking the stride of her speech.
* Ron's random CatapultNightmare gives us this gem:
-->'''Ron:''' [[WakingNonSequitur Spiders! Spiders! They want me to tap dance. I don't wanna tap dance!]]
-->'''Harry:''' ''[complete deadpan]'' You tell those spiders, Ron.
-->'''Ron:''' Okay, I'll tell them... ''[passes out]''