I think, you could have placed Solaris higher. It's a really thought provoking film, although it falls a bit into science fiction genre, something that Tarkovsky called an artistic failure and tried to make Stalker genre-less. As a personal opinion, I don't put The Sacrifice as number one. The Mirror is a better film, Solaris is a better one, and of course, Stalker is definitely better (definitely in my opinion).