I, like so many others (Harry included), couldn't make an unbiased judgement of Snape's character because HE KILLED DUMBLEDORE D: I was pretty distraught... so I couldn't see him as a good guy. I hated him. My mum believed in him though, and now I love him again smile
I never saw the extent of good guy that he was but I knew that Dumbledore wouldn't have trusted him if there hadn't been a very good reason. I'd say being madly in love with Harry's mother and continuing to love her well after she died is a good reason.
Seriously never saw that whole thing coming, I hadn't expected her to add so much depth so far in.
After the first book, I thought of Snape as an example of why Slytherin House is accepted.
Snape is annoying, but very effective- he was the only professor wise to Quirrell's gambit.
(Honestly- if Quirrel is GOOD with trolls, why the panic and passing out? That's suspicious.)
After Book 5, I was certain he was a good guy. Snape was the only one who could notify the
OotP about the Death Eaters in the MoM- and his announcement was the direct cause of the
DE's losing what they set out to accomplish- in fact, being discovered in the process.
I love Snape and when I read the end of Half-Blood Prince I was like "Hmm...there's something fishy here."
My friend totally didn't believe me when I thought he was still good and when we got to the end I was just like emotion_awesome.
I guess I'd never really thought about it much. I went along with the story. Most of me was just confused, but maybe a small part thought that he was living two different lives; one as Voldemort's faithful Death Eater, another as Dumbledore's loyal potions master. He's just a very tricky character, which makes it so unbearable to put those books down!! xd
I believed him to be a good person, since Dumbledore trusted him,
but after book six I hated him, thinking he had really betrayed Dumbledore.
After we learned of his past and his devotion to protect Harry up till the very end
I was sort of ashamed that I had hated such a character as Snape.
Im not a rabid fan girl of his, but I do place him in a high level of my favorite characters,
being on par with several other teachers, but below Luna and Neville.
(Always knew he was going to become a god one day.)