The first physical fight scene between Jack, Sandman and Pitch is pretty wild, with Jack using his frost powers a la Iceman, and Sandy basically constructing two giant whips made of dream sand, which he uses to lay a smackdown on Pitch.
Pitch is no slouch either, utilizing a massive scythe made of nightmare sand.
Even cooler after he pretends to be defeated, he tells Sandy, regarding the dreams that he messed with and turned into Nightmares, "You can have 'em back."
Also, the fight scene against Jack and Pitch, if only for the quick, fast-paced, and amazing visuals that accompanies it.
Pitch corners the Guardians, Jack, and Jamie in an alley corner. Jack's solution for escaping? Hit Pitch in the face with a snowball while he's bragging. The brief moment of Pitch and the nightmares registering what happened buys enough time for the gang to escape and get Jamie's friends.
The Final Battle: Children can use their wonder to kill the Nightmares, and Santa and the Easter Bunny summon their Yetis, elves, and giant moving statue eggs. We can even see a yeti fight a nightmare in the background, killing it by smashing the dark horse with both his fists.
Sandy's rebirth, and subsequent asskicking of Pitch.
Jamie's moment where he proves he's not afraid of Pitch, and the golden sand starts to return, overpowering Pitch's darkness.
After owning Pitch again, Sandman, fresh from being reborn- undoes all of Pitch's work in a few short minutes. Goes to show just powerful the most senior member of the Guardians really is.
The moment where Jack has proven his heroism to the other guardians, and so North officially makes him a guardian.
After the climax, Tooth tosses Pitch a quarter then punches him in the face, knocking out one of his teeth, and says "And that's for my fairies," while giving him an amazing smirk.
Made more awesome (and funnier) by the fact that Pitch earlier snarked to her "What are you going to do? Put a quarter under my pillow?" It wasn't under a pillow, but still makes for a nice "screw you" to him.
When Pitch is at his strongest and the Guardians (aside from Jack) at their weakest, he mocks the assurances they give to the children by asking "Who will protect the Guardians?" Jamie and the other children walk forward, saying that they will protect them. Against the Boogeyman, and his army of horrific nightmares. And when the nightmares charge on Jamie and the children, they stand their ground, and the nightmares turn to golden sand in response, leading to all the Guardians regaining their powers.
Sandman's death at the hands of Pitch. While he looks shocked at first, he never really appears to be scared, choosing instead to give Pitch an impressive death (no pun intended!) glare. Not to mention that the black sand appears to be causing him terrible pain, which makes his stoicism even better.
When he gets restored at the finale, he gets to give Pitch another equally impressive glare with a great little finger wag that precedes Pitch's immediate ownage by golden sand whip.
One can be reminded of the book Sandy first appears in - When Sandy is first fighting off the Nightmares, he drags them up to his cloud, gives them a Death Glare (like the one he gives Pitch in the movie) and tells them - actually speaking - that "You are not real. You are not true. You are nothing."
The moment when Jamie spells out exactly why Pitch will never win. Because nobody has to tell kids that nightmares and fear and terrible things exist; everyone knows the Bogey Man is real. Pitch wasn't ignored because nobody believed in him; he was invisible because children refused to acknowledge him. If he had used his powers for good—spreading fear to people who wanted to hurt children, for example—Pitch could have been seen and believed in. And Jamie lets him know it.
"I do believe in you. I'm just not afraid of you!"
Its easy to dismiss it at first, but the sequence of Pitch taunting Jack in his domain is one of the best in the film between the dialogue delivery, exceptional lightning, use of varied shot angles, and design of the lair. When you're in his domain, Pitch is genuinely in control and true to the being the Boogeyman himself; he can be truly creepy. The moment he fades into the shadows in the end like the Cheshire Cat top it off with a cherry.
That sequence was pretty awesome on a more technical level too—the animation, camera angles, coloring and art were all amazing for that scene.
Baby Tooth gets one. In Antarctica, when Pitch is holding her hostage and offers her in exchange for Jack's staff, but then goes back on his offer once Jack gives him the staff, she pecks his hand, which is several times bigger than her, with her beak.
Not only that, but when Pitch is actually making his offer, it cuts to her. You can't understand what she's saying, but you can tell she's telling Jack not to do it.
The ending, on top of being heartwarming - just, Jack's final lines, and Desplat's score is so rousing and exciting that you can't help but get goosebumps.
Take it as Word of God or Word of Dante as you'd like, but of note is that Johane Matte, a storyboard artist who won an Annie Award for her work on this film, has created a slew of independent comics that give some really interesting insights to Pitch, such as his backstory and his relationships with some of the other Guardians and even a few humans.
One of the comics has Pitch having an encounter with one of his last believers, a man who remembers him from his childhood nightmares. The man turns out to be none other than H.P. Lovecraft. That's right, folks! Pitch Black inspired the Cthulhu Mythos!