2009, Disney Hyperion Books for Children
Series: Book 5 of Percy Jackson and the Olympians
The Good: The Last Olympian wrapped up Percy's story arc perfectly while leaving things open for another character to take over at a later date (which I believe is exactly what Riordan went on to do.) Everything pertaining to Percy and his friends here was covered, as well as the current struggle between the gods and the titans. I especially loved how the love triangle was wrapped up, with a great explanation as to why things worked out the way they did.
The Bad: There was a little too much action in this book. While that's to be expected in the final book in a series, it sort of deadened the excitement for me. The other books in the series mixed action with introspection and educational fact and I felt that The Last Olympian sort of lost everything else the series was before in favor of an explosive ending.