I suspected when I first read OotP that Snape liked Lily, it was the stereotypical guys being horrible to girls they like sort of thing. Also explained his hate for James. Me and a friend spent many nights arguing over this, you can imagine how happy I was when all was revealed in DH .
I have always like Snape, I think it was the mystery of the character that drew me in, wanting to know more, always suspecting things wasn't as they seemed.
I'm re-reading the books at the moment, on PoA one of my favourites . I always love reading about the past when Harrys parents was at Hogwarts.