Michael, the baby in the pink footie pajamas, sticks a cannonball in his teddy bear, lugs it all the way up the ship's mast, and uses it to knock out an oncoming, sword-wielding pirate. This earns him the moniker "Bear Killer" among the Lost Boys.
Peter's duel with Hook at Skull Rock and subsequent rescue of Tiger Lily.
The duel with Hook on his ship at the end of the movie is even better.
Hook: So you want a splash, Mr Starkey? I'LL GIVE YA A SPLASH!! Who's next? Peter Pan:You're next, Hook! This time you've gone too far!
The pirate ship is covered in fairy dust and soars into the sky to return the Darlings to London, against an orchestral variation of 'You Can Fly'.
Tiger Lily, who must be no older than Wendy, goes to her death-by-drowning with a cold, aloof expression all the while. Defiant to the End, indeed. (Of course, Peter rescues her, but she wasn't aware he was anywhere near her until the water was nearly over her head.)
The opening credits recap the events of the first film pretty admirably, adding a medley from significant songs.
Hook's first appearance, soaring right over right past an entire squadron of attacking Luftwaffe, which was Nazi Germany's most deadly, effective, and feared military air force, without being spotted.
The entirety of the song "I'll Try". First it rips your heart out as a tender song about the loss of childhood the main character is facing, having grown up in World War Two. Then it becomes a musical crowning moment of awesome as Tinkerbell comes alive and it's clear that Jane has learned how to believe in something.
She then proceeds to trounce Captain Hook with much confidence and aplomb alongside Tink to spectacularly save Peter and the Lost Boys. It would be almost into Large Ham territory if it wasn't so awesome and improbably cool for such a formerly overly-mature character.