As a hardcore fan, I was sure dumbledore was gonna pop his clogs when he started showing Harry all the stuff from the past. Like transfere of knowledge. Hermonine got it right about the half blooded prince didnt she? She just didnt know it was Snapes mother.
As for bad ending, I thought it was great "SINE" Snape Is Not Evil is popping up all over the net with all the reasons why he isnt a bad guy.
As for the films, I enjoy them as films but they dont compare to the books, but I like to see someone elses visual represenatation of something I have in my head.