In my opinoin snape is no hero, but not the vilan. He was a true member of the order. Dumbledore led the order and gave snape tasks in private so does anyone ever think that may be why he seemed so bad cause dumbledore thought the business should be kept between him and snape? I think EVERYONE did their part and that includes snape. I mean hagrid dealt with the dark side and that was on no one orders but everyone seems to like him alot so iit is all just the matter of opinon.