Not much book discussion outside of the "what books are you reading" thread, especially not for science fiction. This is a smart forum with some great readers so lets pool out knowledge and recommend great unique science novels. My favorite are far out, obscure, or crazy stuff like Quantum Thief, Stranger in a Strange Land, Ancillary Justice, Rendesvoiz with Rama, and Nexus. Also preferably would be low price books or on Kindle Unlimited (like my pick) so they can be read for free. I recommend Übermensch by Mathew Babaoye. Blew my mind to have a protoganist with no sense of personal ownership (I mean, they never say or think the word "my" in the book, until near the end...) and who was genetically engineered to be a happy, willing slave for a futuristic, godlike Master. The dystopian world of that far future Earth was really stark and bleak too, although the story is mostly fun little unique chapters about the various services the main character performs for their master. Great action too. Its a cool, weird little story.
The Man in the High Castle. Soon to be a tv series. Written in 1963 by the seminal visionary Philip K. Dick it is one of the founding works of the Alternate History Genre. A story of a Counterfactual world where the Germans won WWII. It won the Hugo in 1963. Dick is one of the very few authors in any genre whose works all explore a single theme, the questioning of reality, either as the main story or as a subtext. I warn you at the outset, Dick is considered one of the best SF authors but most people, including him, also admit he was pure bat(*)(*)(*)(*) nuts and many people say his style is very definitely an acquired taste.
Armor, by John Steakley. Integral Trees and Smoke Rings, by Larry Niven The Culture novels by Iain Banks, but particularly Player of Games, Surface Detail and Use of Weapons Steel Beach, by John Varley The Gaea trilogy, by John Varley (Titan, Wizard, Demon) Ring of Charon by Roger Macbride Allen, despite some wooden characters Hammer of God and Anvil of Stars by Greg Bear
Just to briefly comment on some of works suggested here: The Man in the High Castle. I read the book years ago so I didn't remember a lot from the book when I saw the pilot episode of the TV show. As far as an alternate world story, I've read better but for the early sixties it was probably groundbreaking. Integral Trees and Smoke Rings, by Larry Niven. I love Niven, but those were some of his lessor works in my opinion. However they seem to be set in the same universe as A World Out of Time, which I did love, and read many times. Also I like his Known Space works, including the Ringworld books. My recommendations would include: The High Crusade by Poul Anderson. It's an old book, probably written in the late 50's or early 60's, but it's a great adventure story. Aliens visit an English village in the Middle Ages to collect samples to prepare for an invasion and the Medieval humans turn the tables on the aliens and capture their ship. The attempt to use it to win the Crusades but the alien prisoner tricks them and sets the navigation to take them back to the aliens empire. The humans have to figure out how to work equipment they can't even understand and bluff various aliens that they actually know what they're doing... The World of Tiers Series by Phillip Jose Farmer. A five volume adventure set in a series of artificial pocket universes created by a super advanced species/
Agreed, but the poster was asking for more unusual books, and those two create an interesting world, even if the story and characters aren't his best.
