Book 4 had death, killing, other things that ruled, and the Triwizard Tournament.
Harry Potter and the Goblet of Fire Rocks
The insane guy. The twist is that he really is a bad, bad man. Brilliant! And he's so nuts, he even helps the other side, teaching Harry valuable defenses against the dark arts while playing Mad Eye Moody. (Actually, that doesn't really make much sense, but whatever.) -- fiction editor Steve Wilson
That opening scene, where the caretaker comes upon Voldemort and Scabbers and Voldemort just KILLS him. Pretty shocking stuff for a series where hardly anyone has died, and shattering the formula established by the previous three books. And then the scary, confusing riot at the Quidditch World Cup. This is where Rowling really started making the books a bit more serious, a bit more adult, a bit deeper, a process she would continue with the rest of the series to great effect. This was the book I wasn't even sure I would bother reading, and it was the book that renewed my faith in the series. Best one so far, in fact. -- message board director David Farnell
Hermione and the House Elf Liberation Front. One of the things I'd found vaguely disquieting about Wizard society from the beginning is their disdain for Muggles; not just professional scumbags like Malfoy, but pretty much every wizard suffers from an underlying dislike of us non-magical types. Half-blood Hermione (my favorite character: I always root for the brainy nerd of any team) gets active and takes on another disturbing cultural problem: slavery.
But what I really liked about this is that Rowling doesn't just make it an easy ethical question. The House Elves like to be slaves! Well, most of them. That Dobby doesn't shows that their preference for slavery may be cultural rather than inborn, so she's not just using that as a way of wimping out. And Ron and Harry's desire to sweep this troubling point under the rug feels realistic (who wants to see the dark sides of one's society in a time of danger?), as does Hermione's mounting frustration with them. And how much is Hermione's activism a way of dealing with her resentment at being a "mudblood"? Yes, things are getting interesting. -- David Farnell
Rowling plays fair with us, all the clues are there to try and figure out what's going on. Even if Harry is, like me, too thick to put them together until it's too late. -- staff writer Gary Mitchel
The boys realize that Hermione is an attractive girl. Especially Ron. As a "shipper", this kind of stuff is awesome. Of course I sometimes wonder if Ron's interested in Hermione because she's cute or because she's dating a world famous Quidditch player. -- contributing writer Deanna Toxopeus
You Know Who becomes a master villain. He has a cunning plan, puts determined, smart minions to work on it, keeps his cowardly, stupid minions close at hand where they can't screw it up, and sticks to the plan. If not for Harry's determination and the Priori Incantatem effect from he and Harry's wands being "brothers," he would have succeeded. At last, a cool villain with style and brains (I love his dressing down of his not-so-loyal Death Eaters).
-- Gary Mitchel
Oh yeah, and Draco the Bouncing Ferret. 'Nuff said. -- Deanna Toxopeus
Harry Potter and the Goblet of Fire Sucks
The Triwizard Tournament isn't all that. Give me a wand and some fish bait and I could win the lame thing. Harry subconsciously knew this, which is why he had to go all spazzy saving the French girl's sister and up the excitement a notch. -- Steve Wilson
Ron is a whiny, self-centered baby. He needs to be slapped. Hard. -- Deanna Toxopeus
And hey, Hogwarts faculty: nice magical protection. Cedric's blood is on your hands.
-- Steve Wilson
Until the Quidditch World Cup, the book drags a bit. And everyone but Hermione seems to have their brains turned down about two notches. "Humm, Harry's having strange dreams about You Know Who. Well, can't worry about it now, got a tournament to run." "Someone's breaking into Snape's office on a regular basis. Should we set a trap or something? Naaah."
-- Gary Mitchel
The other sucky thing: Rita Skeeter. Rowling, get over yourself. Just because some journalist exposed your crummy previous marriage doesn't give you license to trash the whole profession. -- Steve Wilson
I bought the hardcover of this one, and I nearly suffocated myself trying to read it in bed, with the book resting on my chest. Has anyone written a mystery story yet where the blunt instrument used to kill the victim is a Harry Potter novel? -- David Farnell