Absolutely amazing! The plot thickens and we are really starting to see the bigger picture here. We start to see more of the connection between Harry and Voldemort, what he plans to do, what Dumbledore means to do, the ministry, everything. This book was also emotionally exhausting. It was a whirlwind of plot twists, teenage angst, and emotional stress.

I loved the characters as well, and they definitely made the story more exciting.
Ginny seems more mature and confident and fierce.
One of my favorites, Luna Lovegood, was introduced. It was annoying to see Hermione antagonize Luna in the earlier parts of the story, but I really can't blame her. Hermione relies on facts and information, while Luna is fond of the mysterious and the unknown. I definitely want to see more friendly interaction between the two in the future.
I also loved Fred and George here, of course! They're my favorites! I loved how their departure somehow united the students, professors, and Peeves on giving Umbridge hell. It was too funny, too brilliant!
Also, 15-year-old James and Sirius were jerks.