Snapedom

Because, unlike you, I'm attracted to characters who do the right thing, not because they are handsome, popular, rich, goofy, immature, or in Gryffindor, but because they have a moral code that guides them in spite of House affiliation.  They do what is right instead of easy.

Good Guy Syndrome states that whenever a character does a good thing, no matter what that character looks like (Roman nose, hair grease, old clothes) or what his personality seems to be, then you must give him/her credit for that good thing. I see that authors are sometimes immune to this - that's a shame.

A Good Guy consistently takes risks that are selfless, such as an Unbreakable Vow, or helping to protect someone else's child, regardless of getting love in return, or even praise from anyone. He will perform an act of healing, or an act of mercy killing, if he thinks it is right.

A Good Guy does stuff because it is the right thing to do.

The Best Guys are the ones who can use their wits and never make reckless mistakes. They are smart all the time, and not just to impress people with jokes, but because it makes sense. Common Sense is always a sign of a Good Guy.

For instance, my idea of a Good Guy would not be a dog animagus who needs to go walkies to the train station to show off, putting the entire Order in danger.

My idea of a Good Guy is not someone who de-pantsed a boy just for daring to be friends with a Gryffindor Girl who is seen as "too good for him." 

A Good Guy is someone who keeps on loving a woman, even when she has tossed him aside for a childish, spoiled, reckless, Draco-esque rival who thinks he is God's Gift.

My Good Guy grew up. He held a job, instead of living off other people's money. He has gone to work every day instead of sitting in his room sulking. He has an office, he teaches school, and he is a Head of House. Eventually, he is Headmaster of Hogwarts, though he is not good enough for a portrait on the wall.

My hero is a "Working Class-Half-Blood Hero." He was not privileged, but he knew how to work hard and study, and that's one of the best things about him. He sets a good example for students, though I see you recently said that Ron and Harry never liked to read much after school - probably much like the "heroes" in the generation before them, who thought Snape was a nerdy dark-arts emo oddball.

My Good Guy keeps on trying to "get through" to certain kids, even when they disrespect him, call him names, melt cauldrons, and even steal from him. He is able to keep trying even when certain kids invade his privacy and never apologize, or when they try to curse him and kill him for helping a dying older man in a tough situation.

My Good Guy carries the Sword of Gryffindor. I can't seem to recall anyone else except our certified Hero, Harry Potter, doing that before. In DH, we have Harry, Ron, Neville . . . and Snape. So by all the canon we have, Snape is a brave Gryffindor - he just wasn't sorted that way by the Hat, more's the pity. Hmmm, James dreamed of that Sword on the first train to Hogwarts, but I can't recall he ever carried it. . .

My Good Guy shows "tolerance." Don't you love that word? He cares about Dumbledore, whatever he thinks of his sexuality - it's just doesn't matter.  Surprisingly, they talk alot about love instead of sex. 

My Good Guy tells off Phineas Nigellus for using the "M" word - "Mudblood." He has changed from the stammering 15-year-old who believed in a pureblood agenda, just as Dumbledore outgrew his own "infatuation" with the idea, along with Draco, Regulus, and even Narcissa Malfoy. He learned Tolerance over the course of his life, which is probably more than we can say about these other so-called "Good Boys" you like to use as your own gold standard.

My Good Guy has never been seen kicking around House Elves. He is not a Slave Owner. He mentions "Elf-Made Wine" to the Death Eaters who visit his home, but we know good and well he could make his own Nettle Wine in Book One, or Bottle Fame or Brew Glory all by himself, thank you.

My Good Guy has actually dueled in the books, and taught Harry how to duel. But he did not die playing around in front of a Death Veil, while taunting a dangerous witch for fun. 

My Good Guy was not perfect - he was snarky, sarcastic, angry, and passionate. I'll grant you that he could be mean - but no "meaner" than any other character you can name, from Fred Weasley to Hermione Granger, who all have their moments. 

But there is one trait Snape did not have - indifference.  He never said "What about Potter?  He'll be OK," and just walked away from him. He was not a "deadbeat" protector.  He went the distance for someone else's child, unlike other popular characters who had to be convinced to take care of their own.

My Good Guy always told the truth, and is there anything greater than that? As Dumbledore said, "The Truth is always Preferable to Lies."

So please, Ms. Rowling, stop telling lies about this character, and admit he is a Good Guy.