An interesting, if overhyped, story.
There are people out there who have declated this series of stories to be, among other things "An instant classic", "One of the greatest series of all time" and even "The resurrection of the fantasy genre." What it is is a fairly interesting and detailed re-imagining of the classic "Hero destined to destroy evil" story line. It has some very interesting ideas, themes and characters (Snape is a particular favourite of mine), but it is far from meeting the overhyped level of greatness its fans often ascribe to it.
There are several things that make it fall short of this lofty goal. Prime among these is
Protection From Editors. There are massive chunks of the fifth, sixth and seventh books that are not only utterly unrelated to the main plot but are also utter snooze fests, large chunks of borderline impenetrable text. Like many authors who reach a certain level of acclaim it is clear that she didn't get any notes, or any notes she got where ignored.
The plot too has a rather scattergun level of quality. Look at the Deathly Hallows. J K Rowling said that she was surprised that no one had asked about Dumbledore having the invisibility cloak when he could turn invisable on his own. Fine. OK. But the information that normal invisibility cloaks wear out after a while is dropped in the last book, and hammered home with an anvil shaped "but they knew one that did didn't they", making the reveal cheaper than a tin foil cauldron. Also, I know that he was an orphan, but how could someone as well read in all things magical as Voldemort be unaware of a common children's story? I mean Grindelwald's symbol is far from secret. Wouldn't Voldemort have investigated the history of this dark wizards? Especially seeing as he once managed to put a decent fight up against the only wizard he feared!
Another annoying thing, brought to my attention for the first time in a press release of a speech of
Terry Pratchett's that he never actually gave because he was worried about it looking like an attack on Rowling, why do the wizard community determinedly shut themselves off from all modern technology? Nothing Wizards are shown to do come close to being able to replicate, say, the Internet. It makes no sense, save for insane level of Xenophobia.
All in all a good story told well, but not the legendary epic its fans seem to think it is.