Digory, having fallen for Schmuck Bait earlier in the book with disastrous consequences, holds fast to his promise to fetch Forbidden Fruit for Aslan without stealing any for himself — even when Jadis suggests that it could save his ill mother's life.
Special mention of Digory calling Jadis out on her temptations, including him passing on her promise of immortality because he doesn't want to be around when all his friend and family are dead. He then explodes on her when he breaks out of her last promise of using the apple to heal his mother, asking just when she started to care so much for his mother's wellbeing.
Jadis beating people off of her with the arm of the lamppost.
Jadis loose in London is basically one afternoon-long CMOA. It's the biggest compensation for any preachiness in C.S. Lewis's books that he had a sense of humor about this kind of thing. For instance, the Running Gag about how this is the best day the housemaid has had in recent memory. And can I get an amen for Aunt Letty? "Aunt Letty was a very tough old lady; aunts often were in those days."
Jadis:(speaking magical words... that don't work)
Letty: Drunk! I thought as much.
It is suggested that even without her magic, Jadis is so beautiful and terrifying and powerful that she really could have taken over England if given the chance.
Aslan singing the world into existence. The described Scenery Porn of that entire sequence deserves to be shown on the big screen.
King Frank. He's a London cab driver that steps up and becomes the first King of Narnia, just because he is willing to protect the Talking Animals.
And his wife, Helen (Nellie), who gets dragged into Narnia in the middle of laundry day and is like, "Hmm? What? Queen? Okay."
The final reveal that Digory will grow up to be the Professor, and made the wardrobe from the first book from a tree brought back from Narnia.
Although it is bone-chilling, the revelation of how and why Charn and every other living thing in that world was laid waste is indeed awesome.
After Uncle Andrew all but flat-out states that he's using a potentially dangerous situation Polly's in (which he put her into) to make Digory do what he wants, Digory says he wishes he were the same height as Uncle Andrew, so he could punch the man in the face.