Snape's on Dumbledore's side:

Dumbledore was asking Snape to kill him at the end of HBP, he was not begging for his life.

Snape rescued Harry several times during his time at Hogwarts.

Dumbledore said he trusts Snape entirely.

"Well – I jus’ heard Snape sayin Dumbledore took too much for granted an’ maybe he – Snape – didn’ wan’ ter do it anymore –" -Hagrid (HBP)
This could refer to Snape not wanting to follow the plans and kill Dumbledore anymore. He finds the task too difficult to accomplish.

"...We are to leave him! Go! Go!" - Snape (HBP)
Snape tries to protect Harry, making it sound as if it's on Voldemort's orders.

"You see, we have never been able to keep a Defense Against the Dark Arts teacher for longer than a year since I refused the post to Lord Voldemort."- Dumbledore (HBP)
He knows that every DADA teacher disappears after a year. He gave the job to Snape in HBP because he knew Snape would have to leave Hogwarts after killing him.

"Hating himself, repulsed by what he was doing, Harry forced the goblet back toward Dumbledore's mouth ..." (HBP)
"Snape gazed for a moment at Dumbledore, and there was revulsion and hatred etched in the harsh lines of his face." (HBP)
Now this is one of my favorites. JK made it obvious that Snape was feeling the same way as Harry felt when Dumbledore asked him to drink the potion. He was repulsed at what he was about to do, but he had no hatred for Dumbledore.

"The Dark Lord, for instance, almost always knows when somebody is lying to him. Only those skilled at Occlumency are able to shut down those feelings and memories that contradict the lie, and to utter falsehoods in his presence without detection." - Snape (OotP)
Snape is a skilled Occlumency so he can close his mind to Voldemort and lie to him.

"That is just as well, Potter," said Snape coldly, "because you are neither special nor important, and it is not up to you to find out what the Dark Lord is saying to his Death Eaters."
"No -- that's your job, isn't it?" Harry shot at him.
He had not meant to say it; it had burst out of him in temper. For a long moment they stared at each other, Harry convinced he had gone too far. But there was a curious, almost satisfied expression on Snape's face when he answered.
"Yes, Potter," he said, his eyes glinting. "That is my job." (OotP)
Note that Snape had a 'satisfied expression' on his face, as if he thought that Harry had finally understood something.

"Don't go blaming Dumbledore for Potter's determination to break rules. He has been crossing lines ever since he arrived here."
Snape protects Dumbledore once again...

Love all those Evy!!! Especially this one:

I never thought of that before! But it makes perfect sense.

Here's one that someone else wrote that I love:
I think that Dumbledore not fearing death is really important to that section because that tells us that Dumbledore was begging for something that wasn't to keep living.

-Why didn't he kill Harry when he was running away from Hogwarts? He only blocked Harry's attacks when he could have easily killed him, since Harry was going nutters. And since Snape has never heard about the prophecy, he has no idea that Voldemort has to be the one to kill him.
-We don't know why DD trusted Snape, so Snape could have partook in his ultimate personal sacrifice or something to that effect. We only get to see what Harry assumes, which doesn't get us very far.

All that you have said makes perfect sense, and you really changed my mind, cuz I never looked at those quotes that way. But the only think thag intrigs me, even tough all the rest makes perfect sense togheter, I can't help thinkin that

If the Snape was a skilled Occlumency he could have lied to Dumbledore too, and make the game turn around :S

This keep knocking my head!

But all the rest is just perfect, and I believe that you'r right, after all Snape was on Dumbledore's side!

Snape has not been trying to save Harry throughout his time at Hogwarts. Every occasion he had he tried to have Harry expelled. What if Voldemort had come back and Harry knew as much magic as Hagrid?
Snape only tried to save Harry during the quidditch match because of the debt he had to James. In the shrieking shack he didnt go in to save Harry from Sirius, he went in to capture Sirius and get revenge for the bullying. He went crazy in there, even when Hermione suggested hearing Lupin and Black out he let his anger get in the way of his reasoning.
In goblet of fire when he is sent to spy on Voldemort for Dumbledore: "Severus," said Dumbledore, turning to Snape, "you know what I must ask you to do. If you are ready ... if you are prepared ..."
"I am," said Snape.
He looked slightly paler than usual, and his cold, black eyes glittered strangely.
Snape's eyes always glitter when he is triumphant or has the upperhand.This also happens during the occlumency lesson Snape and Harry have in OOTP:

"That is just as well, Potter," said Snape coldly, "because you are neither special nor important, and it is not up to you to find out what the Dark Lord is saying to his Death Eaters."
"No -- that's your job, isn't it?" Harry shot at him.
He had not meant to say it; it had burst out of him in temper. For a long moment they stared at each other, Harry convinced he had gone too far. But there was a curious, almost satisfied expression on Snape's face when he answered.
"Yes, Potter," he said, his eyes glinting. "That is my job." (OotP)
His eyes glint and he is satisfied because he has decieved Harry and he has a dark sadistic sense of humour thats shown in CoS when Dumbledore's examining Mrs Norris. Most of his insults are always about someone not being as intelligent as they should be as he considers him self superior because of his intelligence.
Half Blood prince I reckon explained the truth about Snape in Spinners End as it makes sense. Also the argument Hagrid heard between Snape and Dumbledore was I reckon Snape not wanting to spy on Draco anymore and that Dumbledore was pushing too far what with spying on Voldemort and teaching and now having to spy on another person. I reckon that Dumbledore thought Snape was being tempted to return to the dark side but in reality Snape had always been on the dark side, but as he thought Voldemort dead he just kept him self safe as Lucius did by lying about being imperiused.
Dumbledore I believe wasnt pleading for his life but for Snape to resist the dark side because I dont think Dumbledore would have died just to keep up a pretence. The order's side will be imensly weakened and there will be more killings like Hagrid said when Dumbledore was suspended in CoS. Also moral will be even lower in book 7.
Also note that Snape did attack Harry at the end of HBP but Buckbeak saved Harry.

Hehe, to me those sound like reasons Snape is a big ol' meanie, not that he's working for Voldy.
As far as Occlumency goes, I think Snape chose to let Harry see his past so Harry would know what went on, that his father wasn't the perfect little person Harry pretends he was. And I don't think he could have fooled DD for too long. I think DD is kinda squishy when it comes to love and any sort of relationship dealing with it, but evil he can sense, and would have been able to tell what Snape was up to (whether he had used Occlumency or not).

...I doubt he chose to let Harry see the part where there's a little boy crying in the corner and all those moments in his childhood. It shows Snape's weaknesses, in a way, and Snape wouldn't want that.

I agree with that. I think Dumbledore would have sensed it if there was something wrong with Snape.

In his 2nd year, he probably tried to get Harry expelled because he knew what was going to happen with the Chamber of Secrets and didn't want him to confront that. I can't remember any other occasions when Snape wanted Harry to get expelled...

I think he was just blinded by the rage at that moment. He doesn't accept anyone calling him a coward, and what's more, he'd just done something incredibly courageous; following the plan and killing Dumbledore, even though he didn't really want to. Also, before that, Snape says "Blocked again, and again, and again until you learn to keep your mouth shut and your mind closed, Potter!" He's telling Harry what he needs to work on if he wants to eventually defeat Voldemort!

He only tried to expel Harry in chamber of secrets because he has had any other chance to. He didnt know about the chamber of secrets and if he did he certainly would have told Dumbledore if he was loyal to him.
How do you know the blocked again and again thing wasnt just Snape laughing at Harry's weakness. All these things explaining away Snape's badness just seems like wishful thinking to me and that the idea that he killed Dumbledore on Dumbledores orders seems to have come from wishful thinking.
Why would he have looked out for Harry if he didnt think Voldemort would come back?He hates Harry as much as he hates Lupin and Sirius and after Sirius was killed he continued to rub salt in Harry's wounds. If he had known about the chamber of secrets the last person he would have told is Harry. This is before you say so evidence for Snape's loyalty rather than him just being a big old meanie. He gave information that led to an order member's death, emmeline Vance.

You've got a point here... But maybe Snape didn't know exactly what was gonna happen, just that Voldemort had something planned, that's why he couldn't really inform Dumbledore about it. Also, if he really knew about the Chamber of Secrets, he couldn't have told Dumbledore about it, 'cause Voldemort would have known Snape was the traitor.

I don't know, it's just my interpretation.

The thing is, I also have reasons to believe Snape's on Voldemort's side. You see, there's a possibility that he's with Dumbledore just as much as there's a possibility that he's with Voldemort. I'm just more inclined to think that he's with Dumbledore, that's all.

I think Snape could EASILY be with Voldemort and that's why he ISN'T... lol, As an author, I wouldn't want my 'gray-area' character to turn bad when I already had so many other bad characters. On the baddies you have all of the death eaters, voldemort, and more people he recruits in the next book. For good you have the order and a bunch of teenagers. Gray=Snape and Draco. Whether you like him or not, Snape knows his stuff and I believe would more useful (as a storyline device and a potions master) "helping" the order.
Yeah but that happens sometimes in action/police films, to add to the character having to move on and also to show mistakes are made. Adds to the drama

Yeah, I kinda agree with you. I would be a bit deceived if Snape turned out to be one of the bad guys...

Hmmm...that's definitely a good outlook on it. If the obvious points lead to him being on the dark side, then it would make more sense for him not to be...

I know this may sound crazy, and it's probably not true - but what if he isn't really sure himself what he should do? If he's been forced into staying on the bad side, and it's too dangerous to quit, but the good side thinks he's bad so...ok it's getting confusing - what I mean to say is that he could be unsure himself, so he could have actually been working for both sides, trying to keep himself safe. I don't know - it sounds better in my head... it's like when your two friends have fallen out, and you don't know which side to be on, and you want to stay neutral and not upset either of them so they weren't do anything bad to you, so you help out both sides, but in the end, you're just digging your grave deeper...
That definitely sounded better in my head...but if anyone understands...

I'm sure that if Snape wanted to come back on to the orders side then he wouldnt stand a chance as they'd all attack him at once. I doubt any of the order would question Harry's account of what happened on the tower.
I just think Dumbledore isn't always right. He didn't know about the fake moody which resulted in a students death. He messed up on the prophecy. He's not ALWAYS right! He is human afterall.
Many of you say Snape is on the order's side because Dumbledore says so. I say he's on Voldemort's side because Harry says so.

I see what you mean. It makes sense.

Yeah, I understand! I sort of think that too... I've been in that sort of friendship spot more times than I would have liked to admit!
LOL Are you a Harry fan? Harry is my absolute least fav. character. >.< But that's another reason I think JKR would make Snape lean towards the good side, to make Harry wrong so he'll learn more about trust and how things aren't always as they seem.
JKR says that Hermione sometimes speaks for her in the books. Hermione gives Snape the benefit of the doubt quite a few times, which makes me believe that JKR is saying that she gives him the benefit of the doubt and we should as well...
Regardless, JKR has said Snape is her fav. charrie to write, and he's my fav. charrie (along with Draco) to read. Snape=Fun reading time!

Eh...Harry isn't always right either...In fact he's wrong most of the time.

Absolutely.

Yeah, Hermione is probably one of the most intelligent characters in the books, too. Snape is definetely my favorite character to read. Lately I've been re-reading the books, but only the parts in which Snape appears. I'm not so sure about Draco though. I found him boring in books 1-5. I'd have to say Dumbledore is my second favorite character to read.

When Jk wrote Snape's character I wonder if she knew that thoughout all of the books and all the characters that she invented that Snape would be the one that everyone speculated about? I have yet to 100% say yes he is good or bad. I would hope that he would be on the good side only because that is where I would want to be myself. Everything that has been said about him working for the dark side is feasible. As well as the points that argue for him being a good guy. This is why Snape is one of my favorites no matter how you try to spin it no one will know for sure until JK wants them to.

I dunno, she said he's her fav. to write so maybe she was hoping he would be.
For me now, the books are all about Snape instead of Harry, LOL. My anticipation for book 7 is to see what happens to Harry. JK should just forget about Harry and make it Snaperific!

LOL

nice, I kinda have to agree with you! But I love other characters to , so I dont completely agree.
Imagine a book with the same history but seen by the eyes of Snape, he observing Harry from far away, making those lil coments that we all love...

wouldn't that be great?

Yeah, I agree some what. Snape moments are great to read. I look forward to them everytime i read the books. He's one of the reasons I cant wait till Harry gets to Hogwarts. But I am more interested in Voldemort now. He may not be as funny or as likeable as Snape but he is fascinating.

^^ Heehee! I love some of the other characters, but not Harry. I'd love a Snape-point-of-view book! I'd wear out the pages within a couple of days. Lol! I have a shirt that says I <3 Snape and one that says Snape is Innocent Those are my fav. shirts! (I'm such a dork...)
And Voldemort's a freakmonkey! I think he's kinda funny... rofl. Silly Volly.

OMG where did you get thoses shirts? O_O