The movie is #22 on the ArtsAndFaith.com list of 100 Most Spirituality Significant Films. It's a haunting film -bleak, with long periods of silence and little action. Thought-provoking.
It's available online, and you can watch it here from googlevideo:
Slant Magazine closes its analysis with this:
Perhaps Tarkovsky summed it up best when he wrote about Stalker, "In the end, everything can be reduced to the one simple element which is all a person can count upon in his existence: the capacity to love."
DVDJournal describes it as
Ostensibly a science fiction film, like Solaris it is mostly a movie of ideas, with even fewer of the trappings of the conventional sci-fi movie.and quotes the director as saying,
"People have often asked me what the Zone is, and what it symbolizes, and have put forward wild conjectures on the subject. I'm reduced to a state of fury and despair by such questions. The Zone doesn't symbolize anything, any more than anything else does in my films; the zone is a zone, it's life, and as he makes his way across it a man may break down or he may come through. Whether he comes through or not deepens on his own self-respect, and his capacity to distinguish between what matters and what is merely passing."
The review at DVDTalk.com praises the film saying,
This film is a work of art, yet many people won't like it. It is a slow moving film, there are no action sequences or fight scenes, and the most suspenseful segment has a man slowly walking through a tunnel. It is terribly engrossing nonetheless. The movie runs two and a half hours but is never dull or boring.
Much like 2001: A Space Odyssey, Stalker very much has its own pace and rhythm, and how one responds to it depends largely on one’s engagement with the film in general. I’ve always found it so hypnotic that I barely notice the running time
Personally, I think it’s not only Tarkovsky’s masterpiece but one of an infinitesimally tiny number of films that really does make you look at the world in a different way after you’ve seen it
8/20/2009: 366 Weird Movies covers this film, saying "step into Tarkovsky’s strange world and be prepared to glimpse miracles. If you are at the proper wavelength, Tarkovsky will cast a hypnotic spell on you like no other director."