Tarkovsky (Wikipedia) only made about 7 films. Three are science fiction, and all are visually poetic. He made a slowly moving camera over water worth staring at. He's routinely included in the best handful of filmmakers ever, particularly by highbrow SF cineastes. Unfortunately, he has tendencies towards autobiography, Christian and other religious content and untenable aesthetic theories.
The following make direct references to the Andrei Tarkovsky tag.