We've just lost one of my favorite actors, Alan Rickman. He was superb as Colonel Brandon in Sense and Sensibility, highly entertaining as Alexander Dane, the Spock-like character in Galaxy Quest, and perfect as Severus Snape in the Harry Potter movies.
When we were reading the Harry Potter books as they were published, one of the burning questions was: Snape--was he good or bad or both, whose side was he really on? When the first movie came out, and Rowling, who had a fair amount of control over it, wanted Rickman to play Snape, I thought that was evidence that the character would turn out to be good.