Harry Harrison's Deathworld trilogy begins on the planet Pyrrus, where every living thing and nature itself is out to destroy humans. Jason dinAlt--a roguish interplanetary gambler--sets out to find out what went wrong. Harrison's cracking wit is never in question as he upholds the fine pulp tradition of The Stainless Steel Rat. An omnibus of the complete trilogy is also available.
The central character in Solaris is a sentient ocean that humans find impossible to communicate with. The Earth space-station orbiting the planet is practically a death sentence, as everyone who serves on it seems to get the urge to commit suicide. Lem asserts we should accept that there are things we will never understand. Mind-boggling.
Little Fuzzy by H Beam Piper (1962)
Although initially considered as a work of juvenile fiction, over time it has become clear that H Beam Piper's Little Fuzzy is a work of significant sociological importance. As an "uninhabited" planet, Zarathustra is owned by the corporation named for it. The discovery of the indigenous Fuzzies triggers a court case to determine whether or not they are 'sapient'.
Dune by Frank Herbert (1965)
The first and by far the best of Herbert's Dune series - to survive on sandworld Arrakis water resources must be carefully preserved. A political power struggle over an immortality drug sees the hero lead desert dwellers and sandworms into battle and begin his rise to messiah status. A sprawling saga that remains an immensely popular chart-topper.
Inverted World by Christopher Priest (1969)
UK writer Priest's best genre-SF book is a unique perception versus reality tale about a man who leaves Earth to work as a Future Surveyor on an alien world. The hyperbolic planet proves to be 'inverted' - a place where normal rules of time and space have little relevance. Priest is now a noted writer of innovative non-genre fiction.
The Fifth Head of Cerberus by Gene Wolfe (1972)
Three connected tales - best read as a novel - focusing on GW's favourite subjects of identity and self-exploration. Set in a distant French-colonial bi-planetary system, the key players are a clone who confesses the story of his childhood and a shape-shifting alien who impersonates an anthropologist with ironically fatal results.
The Heritage Of Hastur by Marion Zimmer Bradley (1975)
Transitional novel in the popular Darkover series, with Bradley moving away from writing for younger readers and tackling decidedly more serious themes. The relationship with the Terran Empire is at the heart of a struggle on Darkover, where the telepathic inhabitants take sides in a conflict that pits science against religion.
Midnight at the Well of Souls by Jack Chalker (1977)
Lighthearted sci-fi adventure yarn with roguish space freighter captain Nathan Brazil and his morphed companions getting into all sorts of strife on a planet known as the Well World. They set out to solve an ancient mystery, negotiating the planet's multitude of biosphere-dwelling civilisations along the way. Spawned several sequels of significantly inferior quality.