Fans of Harry Potter all have their favorite Professor, and a look at Reddit provides some great debate over who's the best. Some fans pick their favorite based on who the character is as a person, others go by teaching ability, and some choose by how the teacher interacts with their students.
Using a dozen Reddit threads, the entries are ranked based on how many fans pick each teacher. Any reason for the fans' picks counts and a fan choosing multiple teachers counts as a vote for each one. Unsurprisingly, Dolores Umbridge did not make the top ten!
Firenze - Divination
Firenze (Ray Fearon) is a centaur who appears in four of the Harry Potter books, but in just one movie, Sorcerer's Stone. After Professor Umbridge fires Professor Trelawney in the Order of the Phoenix book, Professor Dumbledore hires Firenze in her stead. On the subject of Firenze teaching Divination, user Njdt in the "Harry Potter" Subreddit says, "Firenze taught the subject too in Book 5, and he admitted that it's prone to error at the end of their first lesson... [Trelawney's] predictions are all colored by death. Invariably!"
Fans seem to think Firenze did well with Divination because he says right off the bat that it can be inaccurate. Whereas Trelawney incorrectly predicts someone's death every year. Firenze was also noble for doing this, as it led to him being banished and attacked by his colony.
Albus Dumbledore - Headmaster
Albus Percival Wulfric Brian Dumbledore is one of the most prominently featured characters in the series. He appears in all seven books and all eight movies, although he has just a brief, silent cameo in the film Deathly Hallows: Part 1. Dumbledore was the Transfiguration teacher earlier in his career, but viewers see the Headmaster teach Harry about Voldemort's history in Half-Blood Prince.
On picking a favorite teacher in the "Harry Potter" Subreddit, Ravingravenclaw says, "Mine would have to be Dumbledore. I know the only lessons we saw were with Harry, but I enjoy discussion-based learning. Especially when it's related to theory and research." What Dumbledore taught Harry there was extremely important, because it would all lead to Harry learning about the Horcruxes and how to defeat Voldemort. Other fans highlighted Dumbeldore's caring nature as to why he was the best. Dumbledore is also known for his wisdom about friendship.
Rubeus Hagrid - Care of Magical Creatures
Hagrid is the Keeper of Keys and Grounds at Hogwarts, and he becomes the Care of Magical Creatures teacher in Prisoner of Azkaban. He appears in every book and movie, and he's played by Robbie Coltrane in the films. In "Harry Potter," an anonymous user picking their favorite teacher says, "Hagrid... his lessons were creative and engaging. He knew his stuff and enjoyed experiencing new things along with his students. His lessons with Hippogriffs, Nifflers, and Unicorns were all undervalued."
Hagrid is not only very knowledgeable and caring towards creatures, but he's also an unending friend to Harry, Ron, and Hermione. He's quite literally the gentle giant of Hogwarts.
Pomona Sprout - Herbology
Professor Sprout is the Herbology teacher, and she appears in six of the books. She appears in just two movies, played by Miriam Margoyles. In "Harry Potter," an anonymous user says of Sprout, "I think her methodology of what students learn and when is fairly sensible and comprehensive. She is also pretty fair-minded about handing points out. It also seemed like she noticed Neville's aptitude for her class and really encouraged him."
Fans noted Professor Sprout's kindness and encouraging attitude. Despite this upbeat demeanor, she also bravely fought alongside her students and fellow teachers during the Battle of Hogwarts.
Mad-Eye Moody / Barty Crouch Jr. - Defence Against The Dark Arts
In an interesting pick for best teacher, many fans selected Alastor "Mad-Eye" Moody. Of course, fans know that when Moody was teaching, it was really the villain Barty Crouch Jr. But fans note that Crouch took on Moody's mannerisms and characteristics to the point where he likely taught the way Moody would've. TheFeury also noted, "Moody teaches all kinds of practical stuff, including resisting the Imperius curse, which Harry puts to use."
TheFeury also shares a quote that Dean Thomas says about Crouch in Order of the Phoenix; "Well, he turned out to be a maniac, didn’t he? Mind you, we still learned loads." This is a case of fans saying that despite the teacher being a horrible person, their ability to pass on information was notable. Moody appears in 4 books and 3 movies. Mad-Eye himself is played by Brendan Gleeson. Crouch is played by David Tennant, who was a big British star in a small role for the film.
Severus Snape - Potions
In another case of a teacher being very mean but knowledgeable, many fans chose Professor Snape as their favorite. Snape appears in every book and movie, and he was brilliantly played in the films by the wonderful Alan Rickman. In "Harry Potter," M4J0R_FR33Z3 notes both Snape's skill and mean streak, saying, "[Snape] was a very good teacher. He did have some really s****y ways of doing things, but it seemed that he always wanted to teach the things you needed to know."
Many fans responded to Snape's supporters by calling him abusive. But whether it be for his potions lessons or his life story, Snape had enough votes from fans to secure the 5th spot.
Horace Slughorn - Potions
Horace Slughorn appears in the last two books, and he's in two movies. In "Harry Potter," Jarris123 says, "[Slughorn] has an award system for the hard workers with great potential. He is not mean to the students that don't do well, they just don't get the rewards, which I think would encourage me to try harder. He's generally friendly with an eye for talent."
Some fans accuse the once-retired Potions teacher of favoritism, but others point out Slughorn's passion for his subject and his support for his students. He also joined in the Battle of Hogwarts, protecting his students and fellow teachers.
Filius Flitwick - Charms
Professor Flitwick, the Charms teacher, may not be a major character, but he is one who many think is the best Hogwarts professor. He appears in all seven books and seven of the eight movies. In "Harry Potter," Baratheoncook25 says, "[Flitwick] let his [students] play games. He is fair and didn't have any sour grapes when Harry was [picked] in the Triwizard [Tournament]. He also [talks] back to Umbridge."
Many fans pointed out Flitwick's kindness and patience with his students, something even the best teachers can struggle with having. Fans also noted that Charms itself would likely be a fun and easy-going class.
Remus Lupin - Defence Against The Dark Arts
Lupin was the third Defense the Dark Arts teacher of the series, a role that changed every book. Lupin appears in four books, and David Thewlis plays him in five movies. When picking a favorite teacher in "Harry Potter," CablossD says, "Lupin all the way... he shows full support for his students, has patience, knows what he is teaching and how to teach it well, and can be a fun teacher you know you can get along with."
Many fans cite Lupin as one of their favorite characters overall. Lupin is sort of a second father figure to Harry after Sirius. He also shows great bravery in the face of being afflicted with werewolfism. Lupin is also known for many great quotes full of comfort and wisdom.
Minerva McGonagall - Transfiguration
Minerva McGonagall is the Transfiguration teacher and Deputy Headmistress at Hogwarts. McGonagall just edged out Lupin for the top spot. In "Harry Potter," Eagling says, "Strict yet fair, McGonagall's class is an example of the highest caliber of teaching." This simple summary captures most of the opinions of those who chose McGonagall.
While many fans cited McGonagall's unmatched teaching ability, others also pointed out that she knows when to show care for her students. A notable moment is when McGonagall stands between Harry and Snape in Deathly Hallows.