Update, 9/6/17: 
 Bumping from three stars to 3.5 rounded up to four. 
 This and Order of the Phoenix are a little bloated. I enjoy reading both of them because they're fun, amusing, humorous, and Rowling can write, but there's a lot of fluff to wade through. The Triwizard Tournament drags on a bit, and I think things there could've been shortened without losing any of the story. 
 I'm giving it the extra half star due to the ending. Wow, what a climax! Everything that happens from the time they get to the Triwizard cup to the end is fantastic. The first time I read this I was surprised at how dark everything turned all at once, but it was nice to see the story mature along with its characters and the intended audience. It's not on the level of Stephen King, but... 
 Rowling always does a great job crafting her mysteries, and I enjoy the explanations at the end. This is one of the best in the series, and everything is put together perfectly. This doesn't mean she won't make the occasional mistake, though. According to the rules Harry ought to be able to see the Thestrals pulling the carriages away from Hogwarts at the end, but he doesn't. Rowling says Harry hadn't completed the cycle of grief yet, and that's why, but I think she wrote herself into a corner and came up with a clever explanation for it. She says the Thestrals were in the plan from the start of the series, and perhaps they were, but I think she tripped up with some of the details between this book and the beginning of the next one. She did also say it was a tough choice. She thought about making them visible at the end but didn't want to drop a new mystery at the end of the book. I guess it just felt kind of wrong, and I agree. I can gloss over it, though I don't seem to be doing that right now. 
 Anyway, you know whether or not you're liking this series at this point, so you don't need a recommendation from me. 
 Original Review, 8/12/10: 
 A light/enjoyable read, even if it is a bit long. However, the climax makes it all worthwhile. Also, this book is responsible for taking the series to its darker level, which I always appreciate since dark plots are my cup of tea.