I liked the scene back home at the Burrow - Rowling showing us that the family is still close despite the tension about Fred and George's future career choices. Nice touch with their poking fun at their mother about how the Hogwarts Express could derail. And those who love Mr. Weasley will do so even more here, I'd imagine - he's evidently the more permissive and less strict of the two parents, and is a bit afraid of his wife's temper on occasion (I'm thinking of that excellent scene in the hospital in OotP), but he's quietly competent. Even if I still think it's ridiculous how little he knows about Muggles considering the Department he's in - what, they couldn't have found Muggle-borns who actually had a clue to staff that Department?

The money matter leads to a painful scene between Ron and his mother, followed by Ron being mocked about the robes by Draco, all of it further building up to the big Harry-Ron fight.

Hermione is really on a different level of development in this book, even more than in the previous one, or at least it leads to more differences in vision between her and the male two-thirds of the Trio. The "Boys!" moment when Harry turns out to prefer Quidditch over resting and considering his issues, but also the house-elves issue - part of her growing up and having more of a personal vision on issues instead of merely what she reads in books, while Ron and Harry still seem largely too focused on themselves to have much interest in the subject. Ron's reaction to the money issue might be viewed through the lens of puberty too, I guess. And Harry's crush on Cho. We'll get a lot more about this around the time of the Yule Ball, of course.

First mention, though not yet appearance, of Rita Skeeter, queen of the Daily Prophet's sensationalistic gutter journalism. Its insidiousness is shown particularly by how Mrs. Weasley, despite really knowing better, does let herself be convinced sometimes - in this case because she really doesn't have any other information sources, of course, but later on in the book also on a matter she really should know better about.

And then Moody of course. Quite the entrance there (and first sip of the hip flask, I have a feeling we'll discover a few more throughout the rest of the book).