Good things.
I feel like I spend a lot of time complaining about things in the HP books, but I really do love them and I think JKR is brilliant. I'm re-reading OotP right now and here are a few of my favourite things:
* Harry's departure from the Dursleys: He felt as though his heart was going to explode with pleasure; he was flying again, flying away from Privet Drive as he'd been fantasizing about all summer, he was going home... And, of course, Harry is going into a situation that's as bad or worse than what he's left behind. The wizarding world is no longer a place of escape.
* Mrs Weasley tries to get rid of the Boggart, but it keeps turning into people she loves, lying dead on the floor. This scene vividly brought home the fear and danger they were all living under.
* Detention with Umbridge. The quill that cuts your lines into your skin was chilling and wonderfully inventive.
* Sirius singing God Rest Ye, Merry Hippogriffs.
* Weasley is our King.
* Draco's death threat to Harry. That was the first time that Draco really seemed dangerous. I hope he follows through.
* And my very favourite bit: Fred and George wheeled about to tumultuous applause from the students below and sped out of the open front doors into the glorious sunset.