Here are some good sci-fi recommendations based on popular sub genres!

Plot: Brought up by unfriendly, ossifying nuns, ancient retainers, and countless skeletons, Gideon is ready to abandon a life of servitude and an afterlife as a reanimated corpse. She packs up her sword, her shoes, and her dirty magazines, and prepares to launch her daring escape. But her childhood nemesis won’t set her free without a service. Harrowhark Nonagesimus, Reverend Daughter of the Ninth House and bone witch extraordinaire, has been summoned into action. The Emperor has invited the heirs to each of his loyal Houses to a deadly trial of wits and skill. If Harrowhark succeeds she will become an immortal, all-powerful servant of the Resurrection, but no necromancer can ascend without their cavalier. Without Gideon’s sword, Harrow will fail, and the Ninth House will die.

Plot: Rumors begin to spread of a species of hyperintelligent, dangerous octopus that may have developed its own language and culture. Marine biologist Dr. Ha Nguyen, who has spent her life researching cephalopod intelligence, will do anything for the chance to study them. The transnational tech corporation DIANIMA has sealed the remote Con Dao Archipelago, where the octopuses were discovered, off from the world. Dr. Nguyen joins DIANIMA’s team on the islands: a battle-scarred security agent and the world’s first android. The octopuses hold the key to unprecedented breakthroughs in extrahuman intelligence. The stakes are high: there are vast fortunes to be made by whoever can take advantage of the octopuses’ advancements, and as Dr. Nguyen struggles to communicate with the newly discovered species, forces larger than DIANIMA close in to seize the octopuses for themselves. But no one has yet asked the octopuses what they think. And what they might do about it.

Plot: Founded by a mysterious genius, the archipelago of Prospera lies hidden from the horrors of a deteriorating outside world. In this island paradise, Prospera’s lucky citizens enjoy long, fulfilling lives until the monitors embedded in their forearms, meant to measure their physical health and psychological well-being, fall below 10 percent. Then they retire themselves, embarking on a ferry ride to the island known as the Nursery, where their failing bodies are renewed, their memories are wiped clean, and they are readied to restart life afresh. Proctor Bennett, of the Department of Social Contracts, has a satisfying career as a ferryman, gently shepherding people through the retirement process–and, when necessary, enforcing it. But all is not well with Proctor. For one thing, he’s been dreaming–which is supposed to be impossible in Prospera. For another, his monitor percentage has begun to drop alarmingly fast. And then comes the day he is summoned to retire his own father, who gives him a disturbing and cryptic message before being wrestled onto the ferry. Meanwhile, something is stirring. The Support Staff, ordinary men and women who provide the labor to keep Prospera running, have begun to question their place in the social order. Unrest is building, and there are rumors spreading of a resistance group–known as “Arrivalists”–who may be fomenting revolution. Soon Proctor finds himself questioning everything he once believed, entangled with a much bigger cause than he realized–and on a desperate mission to uncover the truth.

Plot: In a corporate-dominated space-faring future, planetary missions must be approved and supplied by the Company. For their own safety, exploratory teams are accompanied by Company-supplied security androids. But in a society where contracts are awarded to the lowest bidder, safety isn’t a primary concern. On a distant planet, a team of scientists is conducting surface tests, shadowed by their Company-supplied ‘droid–a self-aware SecUnit that has hacked its own governor module and refers to itself (though never out loud) as “Murderbot.” Scornful of humans, Murderbot wants is to be left alone long enough to figure out who it is, but when a neighboring mission goes dark, it’s up to the scientists and Murderbot to get to the truth.

Plot: Thaddeus Valentine, London’s Head Historian and adored famous archaeologist, and his lovely daughter, Katherine, are down in The Gut when the young assassin with the black scarf strikes toward his heart, saved by the quick intervention of Tom, a lowly third-class apprentice. Racing after the fleeing girl, Tom suddenly glimpses her hideous face: scarred from forehead to jaw, nose a smashed stump, a single eye glaring back at him. “Look at what your Valentine did to me!” she screams. “Ask him! Ask him what he did to Hester Shaw!” And with that she jumps down the waste chute to her death. Minutes later Tom finds himself tumbling down the same chute and stranded in the Out-Country, a sea of mud scored by the huge caterpillar tracks of cities like the one now steaming off over the horizon.

Plot: Outside the island there is nothing: the world was destroyed by a fog that swept the planet, killing anyone it touched. On the island: it is idyllic. One hundred and twenty-two villagers and three scientists, living in peaceful harmony. The villagers are content to fish, farm and feast, to obey their nightly curfew, to do what they’re told by the scientists. Until, to the horror of the islanders, one of their beloved scientists is found brutally stabbed to death. And then they learn that the murder has triggered a lowering of the security system around the island, the only thing that was keeping the fog at bay. If the murder isn’t solved within 107 hours, the fog will smother the island—and everyone on it. But the security system has also wiped everyone’s memories of exactly what happened the night before, which means that someone on the island is a murderer—and they don’t even know it. And the clock is ticking.

Plot: Koushun Takami’s notorious high-octane thriller is based on an irresistible premise: a class of junior high school students is taken to a deserted island where, as part of a ruthless authoritarian program, they are provided arms and forced to kill one another until only one survivor is left standing. 

Plot: On the edge of burnout, Vern decides to return to his family in the Sunshine State to start over. Starting a new dead-end job as a custodian at Quasar—a local science facility with a shady motive—he shrugs on his uniform, grabs a mop and bucket, and trudges off to clean up… Black holes? Space-time anomalies? Galactic ooze? Things aren’t entirely what they seem at Quasar, and when Vern accidentally plugs in a mysterious machine and finds himself standing on the brink of the destruction of every planet in the Multiverse, he’s presented with the greatest question of what is the point? 

Plot: A relaxing getaway in paradise, or a death trap? A young man wakes up on a breathtaking beach, but he has no idea who he is or how he got there. Try as he might to piece it all together, untangling this mind-bending mystery won’t be easy when every clue leads to more maddening questions… and the family that welcomes him into their home is not what they seem.