A book which can attract dramatisations by, on the one hand, strokey-beard Russian experimentalist Tarkovsky, and on the other, quasi-Hollywood dream team Clooney and Soderbergh, must be worth a look. Particularly when it's a classic of sci-fi in its own right.
Solaris is set, whether you are reading it now or when it was first published in 1961, at least 150 years in the future and is the story of Kris Kelvin, who travels to the space station orbiting the planet Solaris to prepare a report on the activities and future of the station. Solaris is a planet where the only living organism is the ocean which covers its surface, and which expresses itself in ways ineffable to man and from which he is constantly trying to take meaning. It has given rise to a whole sect of scientists and explorers who term themselves Solarists, and whose fundamental belief is that contact (or "Contact") between humans and the ocean-entity is possible. Lem's main points seem to be the limited ability of mankind to understand other forms of life and their inevitable tendency to anthropomorphise (as I did just then by saying the ocean "expresses itself" - because as humans, we assume that activity must somehow have a purpose), although this shouldn't be confused with misanthropy since, as the character Snow points out to Kelvin, the ocean may no better understand them than they understand it.
There is a suggestion though that the ocean of Solaris has *some* way of knowing its parasites: all the members of the space station have had visitors from their past, created presumably (there I go again) by Solaris. In Kelvin's case this is Rheya, his former lover who killed herself ten years ago at the age of 19, when he left her. She is still 19 now. Kelvin's immediate reactions of guilt and fear melt into something less hostile as he finds that the replacement Rheya has no knowledge of her past or that she is not the real Rheya - and so, effectively, *is* the real one. Eventually a sort of equilibrium is achieved, although the tests his colleagues want to carry out and which could destroy their visitors, leave him torn between forms of knowledge and belief.
What I liked about Solaris was the stately, unhurried pacing, rather like a Shyamalan film; and the matching dispassionate prose, which may have been deliberate or just the result of a combination of Lem's stoical eastern European stylings and the artificial sense of distance that is always a feature of literature in translation. What I liked less about it was the unshakeable feeling that it all could have been done in far fewer pages and with no loss of effect. One difficulty was that the descriptions of the activities of Solaris, because we know early on that there will never be any explanation or understanding for them, come to seem superfluous and slightly boring. So it simply doesn't matter in the end whether the sea's manifestations take the form of (a) throwing up 'symmetriads' made of light stone, or (b) playing the hits of Boney M on the pan pipes. Similarly all the Solarist theory is so much (pink-foam-spewing) marsh gas, imitative scientifickry for the sake of it. Page after page of it.
But it wins me over in the end simply because the book itself displays unknowability that makes it worth revisiting; and because of the considered and ambiguous ending which hefts more emotional weight than you might think in such a cold, cloudless climate.