Fair warning: Prisoner of Azkaban has always been my favourite HP installment, and has actually been one of my most favourite books of all time for over fifteen years, so there's going to be a lot of squealing over this.
Anyway, I've been looking forward to this month since we started our HP re-read because, like I said, I flippin' love this book. And though I have issues with the movie (see below), I've always really enjoyed this one. Let's be honest: one reason is because Daniel Radcliffe has the perfect hair in this one and he's adorable. Also, it's a bit more atmospheric than the previous two, with some (pleasant) scenery changes, and an interesting decision to get the characters out of their school robes and into "normal" clothes (though Harry wears the same blue shirt for the rest of his life apparently...).
As always, there are spoilers ahead.
Best Character: Lupin and, of course, Sirius.
Worst Character: Malfoy's a dick in this one (the whole trying to get Buckbeak executed thing), but even that doesn't compare to the traitor that is Peter Pettigrew.
Best Moment: Any time the Marauders show up/are mentioned. All I want in life is a prequel series about the Marauders. Siriusly.
But if I had to choose a specific moment, you have to appreciate Hermione slapping Malfoy.
Harry and Ron both made furious moves toward Malfoy, but Hermione got there first - SMACK!
She had slapped Malfoy across the face with all the strength she could muster. Malfoy staggered. Harry, Ron, Crabbe, and Goyle stood flabbergasted as Hermione raised her hand again.
"Don’t you dare call Hagrid pathetic you foul—you evil—"
"Hermione!" said Ron weakly and he tried to grab her hand as she swung it back.
"Get off Ron!"
Hermione pulled out her wand.
Funniest Moment: This book marks the first appearance of Sassy Harry. He was, I think, too shy and self-conscious to be snarky in the first two books, but he really starts backtalking here (Sassy Harry is the best Harry).
But the thing that always makes me laugh is the way the Map insults Snape when he tries to crack the code (even if I do feel bad for Snape in later books).
Mr. Moony presents his compliments to Professor Snape and begs him to keep his abnormally large nose out of other people's business.
Mr. Prongs agrees with Mr. Moony, and would like to add that Professor Snape is an ugly git.
Mr. Padfoot would like to register his astonishment that an idiot like that ever became a professor.
Mr. Wormtail bids Professor Snape good day, and advises him to wash his hair, the slimeball.
Most Shocking Plot Twist: Sirius wasn't the Secret-Keeper! Peter Pettigrew is a (literal) rat! Lupin's a werewolf!
Pay Attention To This Bit, It Will Come Back Later: Well, Pettigrew, obviously, especially now that he owes Harry his life. Also, lots of characters who will come into play later: Sirius, Lupin, Cedric Diggory, Cho Chang.
Best Casting Decision: Gary Freakin' Oldman as Sirius Black.
Worst Casting Decision: While I've grown accustomed to David Thewlis as Lupin, I've always been disappointed at how none-wolf like he is when he wolfs out. I get that werewolves are (arguably) more human than animal, but it feels like he stalled halfway through his transformation.
New Dumbledore: I may be in the minority here, but I actually really like Michael Gambon as Dumbledore. Yes, Richard Harris (RIP) had the gentleness and air of wisdom about him, but Gambon has the vibrancy. Despite Dumbledore being obscenely old, he was an energetic old dude and I think his eccentricity shows a bit more in Gambon's portrayal.
Best Moment: A cross between Hermione PUNCHING Malfoy (#girlpower)
And Sirius dramatically talking about how long he's been in Azkaban (which is one of the best reactions you can use in your day-to-day life when you're feeling impatient).
Funniest Moment: Either the Boggart scene or the Knight Bus. Stan Shunpike is an underrated character.
Biggest Upset: WHY DID THEY IGNORE THE MARAUDERS' BACK STORY? THERE IS LITERALLY THE PERFECT MOMENT (in Lupin's office) WHEN HE COULD HAVE BEEN ALL "HEY HARRY, I MADE THIS MAP WITH YOUR DAD/SIRIUS/PETTIGREW", BUT NO. NOTHING. I'm honestly still devastated at how poorly the Marauders were treated in this adaptation.