I'm not usually enthusiastic about science fiction, even though I love reading non-fiction about what we're discovering in space, but every once in a while I come across a science fiction novel that is so good that you don't have to like science fiction to like it. Since most of us read The Giver and Fahrenheit 451 in school, they aren't included on this list, but if you liked those, I'll bet you'll go for:
War with the Newts - Karel Capek
This novel by the great Czech writer satirizes the terrifying political situation Europe and the United States found themselves in during the 1930s, not only attacking nazism and fascism, but also American segregation laws and consumerism. The book describes the discovery of a race of highly intelligent newts, their enslavement by humans, and the war that erupts as a result. Fun fact: Capek is credited as the inventor of the word "robot."
The House on the Strand - Daphne du Maurier
This narrator of this novel has agreed to be a test subject for his biophysicist friend's new experimental drug, which, they discover, allows them to travel psychically in time, experiencing past realities without being able to act within them. Du Maurier doesn't write long pseudo-technical treatises, instead focusing on the effects time travel has on the characters' individual lives and emotions.
Science Fiction Quintet - Madeleine L'Engle
(A Wrinkle in Time, A Wind in the Door, A Swiftly Tilting Planet, Many Waters, An Acceptable Time)
These novels may have been written for young adults, but they bear repeated reading and have much to offer to adult readers. A Wrinkle in Time begins with the revelation that there is such a thing as a tesseract and Meg Murray soon finds herself on an interstellar quest to find her lately disappeared father. The further books continue the stories of the Murry and O'Keefe families. L'Engle's uncanny ability to write fiction about metaphysical, spiritual, and scientific concepts, as well as her complex characters and imagined worlds, makes these novels, particularly the first two, rare masterpieces of young adult literature.
Mara and Dann - Doris Lessing
Lessing has written a lot of science fiction, but I have a particular affection for this dystopian novel about a brother and sister who are the last survivors of their race in a world that becomes less habitable and more dangerous every day. Lessing has a gift for character study, which is never overwhelmed by the demands of the science fiction genre. And if you like this one, there's a sequel!
Science Fiction Trilogy - C.S. Lewis
(Out of the Silent Planet, Perelandra, That Hideous Strength)
The hero of these novels is a philologist, Dr. Ransom, who finds himself swept into cosmic events while on a walking tour in the country. He travels to Mars and Venus and then starts an underground campaign against a disturbing organization on Earth, which conducts reprehensible experiments. Lewis creates a fascinating and morally complex world, rife with mysticism and political chicanery. The third book in the trilogy gets my vote for the best science fiction book ever written.
A Voyage to Arcturus - David Lindsay
This philosophic novel, reminiscent of Chesterton's fiction, set on an unexplored planet in a distant solar system had a heavy influence on Lewis's science fiction writing and its engagement with moral questions about good, evil, and moral choice sets it apart from run-of-the-mill science fiction. Maskull and two companions travel to the planet Tormance where Maskull undergoes a series of transformative experiences ending in a final revelation of cosmic significance.
Frankenstein - Mary Shelley
Mary Shelley's masterpiece, one she would never top, is the seminal science fiction work, a game-changing monument to the scientific imagination. Frankenstein is being continually rewritten and adapted, but it hasn't been the slightest bit tarnished. A moving portrait of perverse and misunderstood humanity, the book tells the story of a scientist obsessed with the regeneration of human life and the creature he creates. I've yet to meet anyone who didn't love this book.