Harry Potter and the Chamber of Secrets  - J.K. Rowling
Really, thoroughly enjoyed this one.
Once again, there isn't much that I can say here that hasn't already been said.
A few of the things that I liked the most:
First off, I love that we get to see more of the wizard world home life with the Weasley's. I absolutely love the way their home is described as being a bit cluttered, but comfortable and warm. I would love to go there for a day, even if just to go through Mr. Weasley's garage of enchanted muggle objects. I'd love to see what's done with every day things that we don't think about.
I just loved when Mr. Weasley punched Lucius Malfoy in the bookstore. I even cheered for him out loud and got more than a couple funny looks, but that's okay. He and his son both deserve it. And to call Hermione a Mudblood. Horrible. Screw all the Malfoys.
Poor Ron trying to do that slug spell and his wand backfiring. Still, it was funny and very creative.
This entire book shows Rowling's creativity. There are so many points in the story when I just sat and thought, How did she think of that. House Elves, for example. If I were writing this, I wouldn't have thought of that. And Nearly Headless Nick's party.
I was a tad confused at the end with Tom Riddle being Lord Voldemort, but I figured it out fairly easily. It just threw me.
I felt like this story didn't necessarily go with the first one in terms of plot. They're very different, but obviously to the same means of Voldemort trying to return.