Harry Potter and the Chamber of Secrets by J. K. Rowling

"Come … come to me … Let me rip you … Let me tear you … Let me kill you …"

After his explosive first year as Hogwarts, School of Witchcraft and Wizardry, Harry Potter returns to the Dursleys, who are meaner, fouler, and nastier than ever. And being cut off from the Wizarding World is proving even more difficult than Harry thought. But on Harry's twelfth birthday, he gets a magical visitor of the most peculiar. And what this visitor has to say is even stranger: "Harry Potter must not go back to Hogwarts."

But Harry does return to Hogwarts and once there, a terrible, ancient monster begins to terrorize the students. Harry, Ron, and Hermione  don't know who has released the wicked creature, but the rest of the school has an idea who the culprit might be: Harry Potter.

One of the things that I love most about the Harry Potter series is that it is FUN. Pure and guilt-free FUN. Of course, this FUN dwindles somewhat as the series progresses, becoming more sinister and serious. But the first four of the series take me back to summertime as a teenager. The only other book that has achieved that feat was Percy Jackson and the Lightning Thief. 

Absolutely awesome.