Well, 'The Yiddish Policemen's Union' by Michael Chabon is an interesting alternate history science fiction book. It posits a world where Alaska became a temporary homeland for Jews after World War II. Also, 'The Difference Engine' by William Gibson and Bruce Sterling is set in a world where the computer was invented much earlier in the 19th century due to different historical developments. And Kim Stanley Robinson's 'The Years of Rice and Salt' is an alternate history where the Black Death wiped out most of Europe's population, leading to a very different world.
A must - read is 'Hyperion' by Dan Simmons. It's a great blend of science fiction and mythology. 'The Time Machine' by H.G. Wells is also very important as it was one of the early works exploring time travel. And 'I, Robot' by Isaac Asimov which introduced the famous Three Laws of Robotics.
One that stands out is 'The Shining' by Stephen King. Although more often considered a horror novel, it has elements of the supernatural that could be seen as science - fictional. 'The Martian Chronicles' by Ray Bradbury has some disturbing and thought - provoking moments that border on horror. And 'Fahrenheit 451' by Ray Bradbury also has an element of horror in its dystopian vision of a world where books are burned and free thought is suppressed.
Definitely 'The War of the Worlds' by H.G. Wells. It was one of the first to really explore the idea of an alien invasion and the fear it can cause. Another top pick is 'Starship Troopers' by Robert A. Heinlein. It has great military science - fiction elements and makes you think about citizenship and duty. 'Slaughterhouse - Five' by Kurt Vonnegut also has science - fiction elements in its time - traveling narrative.
One of the great science fiction romance books is 'The Host' by Stephenie Meyer. It combines a love story with a science - fiction concept of alien invasion in a unique way. Another is 'These Broken Stars' by Amie Kaufman and Meagan Spooner. The story of two survivors in a crashed spaceship has a strong romantic sub - plot. 'Cinder' by Marissa Meyer is also a great pick. It's a retelling of Cinderella in a science - fiction world filled with cyborgs and a sweet romance.
Well, 'The Peshawar Lancers' by S.M. Stirling is a remarkable alternate history science fiction book. It imagines a world where a meteorite strike in the 19th century changes the course of history. 'Dies the Fire' by the same author is also good, with a world suddenly losing all modern technology. 'The Yiddish Policemen's Union' by Michael Chabon is worth mentioning too. It's set in an alternate Alaska where a Jewish homeland has been established.
One great AI science fiction book is 'Neuromancer' by William Gibson. It's a classic that really introduced the concept of cyberspace and had a huge influence on the genre. Another is 'I, Robot' by Isaac Asimov, which explores the Three Laws of Robotics in various interesting scenarios. And 'Snow Crash' by Neal Stephenson is also a must - read, with its unique take on a future where the virtual and real worlds are intertwined.
One popular alternate history science fiction book is 'The Man in the High Castle' by Philip K. Dick. It imagines a world where the Axis powers won World War II. Another is 'Bring the Jubilee' by Ward Moore, which has a Confederate victory in the American Civil War as its alternate history premise. And 'Fatherland' by Robert Harris is set in a world where Nazi Germany won the war.
Among the most influential alternate history science fiction books, 'The Difference Engine' stands out. It was one of the first to really explore the idea of how changes in technology in the past could have a huge impact on the future. By imagining an early invention of the computer, it shows how different our world could be. 'The Years of Rice and Salt' is also influential as it takes a global event (the Black Death) and shows how it could have completely reshaped the world's history and cultures.
One great alternate history WW2 novel is 'The Man in the High Castle' by Philip K. Dick. It presents a world where the Axis powers won the war. Another is 'Fatherland' by Robert Harris, which imagines a victorious Nazi Germany in 1964. And 'SS - GB' by Len Deighton, set in a Britain occupied by the Nazis.
Yes, alternate history is often classified as a subgenre of science fiction. It explores 'what if' scenarios by imagining different outcomes of historical events.