Harry Potter and the Philosopher's Stone tells of a boy named Harry Potter who had to live with his relatives, the Dursleys, after his parents were killed in a car crash. Later, when he receives an offer letter from the Hogwarts School of Witchcraft and Wizardry, he finds out that he is actually a wizard and that his parents were killed by a very powerful Dark Wizard, Lord Voldemort. In this book, Harry faces Lord Voldemort for the first time (second, actually, if you count the time Voldemort tried to kill when he was still a baby) when Lord Voldemort tries to seek the Philosopher's Stone which can give him immortality.
Since I've read HP 1 to HP 7, I can see the difference in Harry's personality in each of the books. In this book, JK Rowling did a good job of portraying Harry as a young, naive and innocent 11-year-old wizard who (sometimes) makes immature decisions, afraid to confide in adults (such as his Headmaster Albus Dumbledore) while trying to get used to his identity as a wizard.
Harry enters his second year at Hogwarts in Harry Potter and the Chamber of Secrets. In this book, Harry faces the heir of Slytherin who has opened the Chamber of Secrets. I don't like this book much because there was a part where everybody avoided talking to Harry because they suspected he was the heir of Slytherin. Only when Harry's best friend Hermione is attacked do they change their minds. Another reason I don't like this book much is the way Harry and his other best friend, Ron Weasley arrived at Hogwarts (by flying Mr. Weasley's Ford Anglia) because they started the new term with a whole lot of trouble due to their bad decision-making. But never mind...they're still immature here. But I loved the part where Harry fought the Basilisk in the Chamber of Secrets...considering the fact that he's only 12 years old.
In Harry Potter and the Prisoner of Azkaban, everyone in the wizarding world and the muggle (people who don't have magic) world are on the alert for a high-profile murderer, Sirius Black, who has managed to escape from Azkaban, the wizard prison. Extra precautions are taken to protect Harry since Black is believed to be trying to capture Harry and bring him to Lord Voldemort. Halfway through the story, however, Harry and his friends learn that Black is Harry's deceased parents' best friend...not only was he the best man at his parents' wedding, but they also appointed Black to be Harry's godfather and guardian should anything happen to them. Harry and his friends also learn that Sirius Black was framed by another old friend, Peter Pettigrew, so they have to save Black from the Dementors (the Azkaban guards). The method used by Harry and Hermione to save Sirius Black in here is really ingenious. Although its kinda disappointing that they weren't able to clear Sirius' name and prove his innocence, there's a reason for it all in one of the later books.
Harry Potter and the Goblet of Fire is my favourite book of the first four books. There's a lot more magic in this book, not to mention a number of useful spells which I wish were real (eg, Accio! No need to keep getting up to fetch that something you've left somewhere). In this book, Harry is chosen as one of the school champions in the Triwizard Tournament...but the mystery is, Harry does not even fulfill the age limit required to enter the tournament! So who submitted his name as a participant?? After successfully performing all three tasks, Harry and Cedric Diggory, another Hogwarts champion, tie for the first place and grabbed hold of the Triwizard Cup at the same time. To their surprise, the Cup is a Portkey (which is an object that can transport you to the designated place when touched) and it transported them both to an empty graveyard, the place where Lord Voldemort has chosen to resurrect himself. My favourite part in this book is the Priori Incantatem chapter, the part where Harry duels with Voldemort. The first death in the HP series also occurred in this book with the death of Cedric Diggory. When Harry returns to Hogwarts, he told Dumbledore that Lord Voldemort has returned. Unfortunately, the Minister of Magic at that time, Cornelius Fudge, did not believe in Harry's story.
In Harry Potter and the Order of the Phoenix, the Ministry of Magic is trying very hard to deny rumours that Lord Voldemort is back by using the Daily Prophet to portray Harry and Dumbledore as crazy, etc. The Order of the Phoenix is an Order established during the time Lord Voldemort was still in power (Harry's parents were among the members of the Order before they were murdered). The Order was re-established to start planning various strategies to overcome Voldemort. One of their tasks in this book is to guard "something" in the Department of Mysteries in the Ministry from Voldemort. Towards the end of the book, Harry sees his godfather Sirius Black being tortured by Lord Voldemort via his scar, which somehow connects him to Lord Voldemort. So he rallies his friends and they all fly on Thestrals to the Ministry to try and save Sirius. However, it turned out that the vision was merely a trick to attract Harry to the Ministry, because Lord Voldemort wanted Harry to take a prophecy regarding Harry and him. A battle ensued between Harry & his friends and the Death Eaters. The other members of the Order turned up just in time to help them fight the Death Eaters. Unfortunately though, Sirius was killed in the fight. Sirius' death was a big blow to Harry, because he had now lost the man he looked upon as his parent. One good thing that came out of the fight at the Ministry is that the Minister and several other wizards turned up just in time to see Lord Voldemort before he disappeared, so now they have to accept the fact that Lord Voldemort is really back.
Harry Potter and the Half-Blood Prince starts by describing the deaths and terror faced by the people as Lord Voldemort and his Death Eaters start killing Muggles and Muggle-borns. In this book, Harry takes private lessons with Professor Dumbledore - together, they go back into the memories of certain people to learn about Voldemort's childhood as they attempt to understand him. Along the way, they learn that Voldemort had created seven Horcruxes which are hidden in different hiding places to prevent him from dying. Harry follows Dumbledore to a certain cave by the sea to destroy one of the Horcruxes, but when they return to Hogwarts, they discover that it had been attacked by a group of Death Eaters. Dumbledore dies in this book, leaving Harry with the basic knowledge of what he has to do in the future to overcome Lord Voldemort. I can still cry each time I read the part describing Dumbledore's funeral, because Harry is now all alone - his parents, his godfather and now his headmaster have left him in their efforts to protect him from Voldemort.
I almost didn't want to read Harry Potter and the Deathly Hallows, because this is the last book in the series and that there will be no more Harry after this. But of course, I had to start reading the minute I bought the book. In this book, Harry sets out with his friends to find and destroy the seven Horcruxes created by Voldemort. The ultimate battle then takes place between Harry's side and Voldemort's side. I loved reading the battle part - it seems so much cooler and riskier to battle using magic instead of firing canons of dropping nuclear bombs on the enemy. Thankfully, JK Rowling created a "19 years later" chapter which lets her readers know what happened 19 years later. I don't think I'd be fully-satisfied otherwise.
JK Rowling has an exceptional style of writing regardless when she is describing sceneries or when she's playing with her characters' emotions. She is also quite witty and manages to keep her readers laughing (or crying) at all the appropriate moments besides keeping her readers hooked and wanting to keep turning the page to find out what happens next. Each time I re-read a HP book, especially the last one, I really appreciate the little details written in the earlier books which then play their own role in the end. And to be honest, I don't watch the HP movies anymore because the movie plots are too different from the actual books, so I don't see how they're going to portray the Horcruxes part and stuff. There are too many important details left out...but then again, movie-makers only have a couple of hours to cram in around 600 - 700 pages.
I have repeated all HP books countless of times...and if a new HP book was coming out, I'd read all the previous HP books and surf the HP websites in anticipation of the new book. Oh, the thrill of it! Too bad there are no more HP books coming out though. However, there are other HP-related books such as the newly-published The Tales of Beedle the Bard, which is a fairy tale book mentioned in Harry Potter and the Deathly Hallows. Even though HP is now over, all I have to do is open the cover of the first HP book to make him alive again. (Sorry if that sounded cheesy.)