One can often wonder how Hogwarts never got sued by thousands of concerned parents (Muggle or otherwise). The number of child-endangering incidents in that school is too damn high. At least it was ever since a certain Potter boy enrolled - probably just a coincidence... or a Dark Lord, who knows? Nevertheless, Hogwarts has more or less escaped that sort of scrutiny; perhaps one of the reasons for this is its quality teachers.
Save for the Defense Against the Dark Arts subject, the "academic" personnel of the school are quite excellent. The teachers and how they continuously usher in generation after generation of wizards and witches is worth every Galleon, Sickle, or Knut spent on Hogwarts. Despite some major hiccups in certain lessons, this is more than compensated for by the best professors of Hogwarts. Here are ten of them.
10 BARTY CROUCH JR.
Here's when Hogwarts really should have been shut down. They unwittingly let an active Death Eater near their students and even let him teach the most important lesson for Hogwarts at the time. Despite that, Barty Crouch Jr. did surprisingly okay as Alastor Moody. He even taught lessons in advance.
He also introduced the three unforgivable curses and how to combat them to students in a time where Death Eaters were regrouping. Granted, that's probably the only lesson he knew how to teach, being a Death Eater and all. Another big surprise is the fact that almost no one was harmed by the dangerous Barty (apart from Neville's innocence or Malfoy's pride).
9 ROLANDA HOOCH
P.E. might be a boring subject for some, but certain teachers can make it an enjoyable respite from all the theoretical information. Hogwarts' Professor Rolanda Hooch is one of those teachers. She doesn't appear much beyond the first film/book but her role was quite crucial in the students' development as Houses. That is if you can get past her appearance; she looks like Snape's female twin.
Anyway, she's the one responsible for introducing Quidditch or broom-riding to the first years. Funny enough, she actually left her class on the first day of school but that was Neville's fault. Anyway, had she not done that, Harry probably would not have discovered his hidden talent for Quidditch or flying. Apart from being a professor, she also sometimes acts as the Quidditch referee or umpire. That's a huge plus in any students' eyes since she most likely doesn't have favoritism, unlike the next professor...
8 HORACE SLUGHORN
It seems nine out of ten Slytherins you meet are often up to something disagreeable. Professor Horace Slughorn is no exception. He's a Slytherin through and through from childhood to seniority. While his favoritism is quite detrimental (he even has his own awkward club for it) to the learning process, there's no denying that he's brilliant.
In fact (and if you can recall), Dumbledore holds tremendous respect for him. Even Voldemort wanted to recruit Slughorn in his Death Eater army for the brilliant old man's abilities and knowledge. Other than that, there aren't really many people who could replace a job that's perfect for the self-proclaimed Half-Blood Prince...
7 SEVERUS SNAPE
There he is, our favorite emo prince. For a long time, Professor Snape held the post of Potions Master before switching over to Defense Against the Dark Arts and being replaced by Slughorn. How'd he fare as Potions teacher? Not pleasant at all. Before Snape had been redeemed to kingdom come in Deathly Hallows or before Dolores Umbridge was introduced, we only knew Snape as the terror teacher.
He's the professor who gave disheartening paper deadlines and allowed nary a squeak in the classroom while he's talking. Anyone who tries to talk back or show any sign of deviance gets humiliated. Mostly it was Potter... and friends... or anyone from Gryffindor. While you will learn a lot from Professor Snape, you'll also hate him for it.
6 POMONA SPROUT
Herbology might sound like a dull subject but Hogwarts' Professor Pomona Sprout somehow makes it fun. Often, her subject involves equal parts theory and practice, which is always a fun way to learn by any standard. It also appears that Professor Sprout's lessons are one of the most structured in Hogwarts.
During each and every class, Professor Sprout advances the lessons organically and introduces gradually newer and rarer plants. It's highly similar to real-world academic teaching methods. As a result, her subject is relatable to us Muggles. Not to mention Sprout also sports that jolly aunt vibe and prioritizes the safety of any student in her classes.
5 FILIUS FLITWICK
It's hard to absorb your lessons and actually learn something if your teacher appears impassionate about them. Luckily for the students of Hogwarts, Professor Filius Flitwick of Charms class can be summed up with one behavior: enthusiasm. It appears that Professor Flitwick also enjoys what his students are learning.
For a lesson as important as Charms in the Wizarding World, this can have resonating effects. If not for Professor Flitwick's keen teaching, Harry, Ron, and Hermione would not have defeated that troll in the dungeon. Beyond that, he also teaches through demonstration yet lets his students figure things out for themselves, improving their resourcefulness.
4 RUBEUS HAGRID
Professor Rubeus Hagrid (who'd have thought?) teaches Hogwarts an equivalent of biology or zoology in the Wizarding World and rightfully so. His subject is called Care of Magical Creatures, which is probably heaven for someone like him. Hagrid getting the role is harmonic as he loves magical beasts in any shape and size (though he usually prefers the big and misunderstood ones).
You'd have to be evil (or a Slytherin) to hate Professor Hagrid's class or teaching methods. They involve mostly practice and knowledge gained through years of experience interacting with the floofs of the Wizarding World. Since they're basically about animals, they take place outside the classroom - a welcome change of pace for any student. It's too bad the films didn't show more of Hagrid's classes.
3 ALBUS DUMBLEDORE
He didn't become the Headmaster of Hogwarts for nothing. Albus Dumbledore, the most powerful wizard in the modern Wizarding World was once but a humble professor at Hogwarts. He used to teach Defense Against the Dark Arts in Hogwarts back in the 1920s and was a notable wizard back then.
He was also one of the few who found a way to work against Gellert Grindlewald while still being a teacher. Even as a Headmaster, one can still learn a lot from Dumbledore. Harry, Snape, even the Ministry of Magic or his own peers have picked up some valuable lessons one way or another from Dumbledore. Besides, who wouldn't want to learn from the world's most powerful wizard?
2 REMUS LUPIN
What do we have here? A modern Defense Against the Dark Arts teacher who was actually useful? That's worthy of a standing ovation. So let's clap our hands for Remus Lupin, one of the few (or only) Defense Against the Dark Arts teacher who knew what he was doing and was also not evil... at least when he's human.
While he has a tendency to bite his students' faces off during full moon, that can be excused. Professor Lupin taught Harry the most iconic spell in the Wizarding World: the Patronus charm (which can also double as a personal Sorting Hat). Moreover, his classes are simply exciting and involve plenty of interaction as well as practical stuff.
1 MINERVA MCGONAGALL
Dumbledore might be the most powerful teacher in Hogwarts, but the most powerful brain belongs to Professor Minerva McGonagall of Transfiguration class. In fact, she's the "Hermione" of her generation, that is, the brightest witch/wizard of her age. As you can imagine, Professor McGonagall is a treasure trove of knowledge.
What's more, she's also an Animagus (people who can willingly transform into animals) herself. That makes her the perfect teacher of her subject. Meanwhile, her classes mostly take place in the classroom and are theory-heavy, but she still allows plenty of room for practical experimentation. Her brain combined with years of experience, a solid moral compass, and being the head of House Gryffindor makes her the best teacher in Hogwarts ever... the best one who didn't leave, at least.