Preening wizard celebrity Gilderoy Lockhart (Kenneth Branagh) is the new Defense Against the Dark Arts teacher at Hogwarts, and he holds a lesson on how to deal with Cornish Pixies, little blue creatures that look like cuddly versions of something Guillermo del Toro might dream up.
Lockhart's ineptitude sees the pixies running riot in the lesson, until Hermione hits them with an immobility spell. It's the facial expressions that really make this moment, as the paralysed pixies float lifelessly past.
Up to this point you had thought Ron's beloved pet Scabbers was an innocent rat, but after being snatched by animagus Sirius Black in his canine form, the rodent is revealed as none other than Peter Pettigrew (Timothy Spall).
Not only is the transformation spot on in terms of visual effects, but the moment is made by Spall's casting: who else could be so convincing as the sleazy ratty villain?
Ron Weasley, Getaway Driver
Part II of Harry's adventures is very similar structurally to its predecessor. It opens with the boy wizard back with his miserable guardians on Privet Drive. If Dobby's visit had shown that the CGI had taken a remarkable bound forward, then Ron Weasley's flying car was proof that they had retained the magical feeling of the special effects.
Later, Ron gets to put his foot down after he and Harry miss the Hogwarts Express, and the Weasley's ever-reliable Ford Anglia has a run-in with the Whomping Willow, but it's Harry's bedroom breakout that has the most charm.
Fans of the books were eagerly anticipating seeing the sport played out on the big screen, but the scenes in the first movie were somewhat disappointing. Action that was clearly greenscreened combined with a match that was impossible to follow resulted in a total letdown.
Chamber of Secrets is the first time the effects could handle the aerial action of the game, and Malfoy's spot as a rival seeker gave some much needed zip to the proceedings, helping to add a bit of tension to the game of 'catch the snitch'.
While the first movie is packed with detail, the visual effects weren't always its strong suit (check out the Quidditch match for example). But when Zoe Wanamaker's Madame Hooch takes the kids out for their first broom lesson, the giddy jerkiness is perfect.
From struggling to summon their brooms into action (oi- they were a bit young for any hormonal metaphors at this point), to mounting them wobbily and ascending jerkily into the air above the ground, it's the little details that make the magic feel real.
"Turn to page... 394"
Snape has been the centre of many of the series' great moments, and he's sure to grab his fair share in the Deathly Hallows two-parter. Here he gives a masterclass in how to grab a class's attention when he storms into the room, magics down the shutters and demands in his inimitable tones that the students "Turn to page three-hundred.. and ninety.. four."
Added attitude comes when he deducts house points from Hermione with a withering "Do you take pride in being an insufferable know-it-all?' and warns the rest of the class not to let an impending Quidditch match get in the way of their assignment: "Loss of limb will not excuse you."
Enter the dragon
The fourth film gets a big boost in terms of spectacular moments thanks to the Tri-Wizard tournament. The strongest pupils from each school (and wild card Harry Potter) take part in series of dangerous, but thrillingly spectacular, challenges.
The first of these involves stealing a golden egg from underneath a dragon. Harry's face-off with a firebreather succeeds where so many dragon movies have failed ( Reign of Fire we're looking at you). The Hungarian Horntail is an untameable ferocious opponent, and the battle finds time for some aerial combat that causes a not inconsiderable amount of damage to the school.
And that's just Round One.
Gambon settles in
It must have been daunting for Michael Gambon to slip into Dumbledore's robes for the third movie: he was succeeding Richard Harris who sadly died just before Chamber of Secrets was released.
Rather than attempting a Harris impression, Gambon comfortably made the role of the eccentric Hogwarts headmaster his own. By the end of the movie he's totally at ease, and nabs one of the Azkaban 's best lines: after sending Hermione and Harry off on a time-turning adventure he pleads ignorance with a perfectly delivered: "Did what? Good night."
Millennium Bridge Attack
It's always impressive in the Harry Potter movies when the archaic world of wizardry meets the über-newness of muggles' London.
Voldemort increases the scale of his attack against the human world by sending the Death Eaters to destroy the capital's Millennium Bridge. Impressive in scale and execution, it's awe-inspiring to see the effects of some destructive conjuring on a recognisable location. That'll grab your attention.
Quidditch World Cup
As the movies progess, the FX teams become ever more adept at handling the Quidditch scenes, and their growing confidence is seen in the brief glimpse we get of the Quidditch World Cup.
As impressive as the vast stadium is though, it's the Death Eaters' attack on the campsite that stays with you, as they hurl flaming projectiles at the tents, while a dark, skull-shaped cloud wafts overhead, indicating the ever-growing power of You-Know-Who…