*excited cooing*

The Doors of Eden by Adrian Tchaikovsky*

The Doors of Eden is something of an experiment in speculative biology, featuring versions of Earth in which various different species were the one to rise to sentience, from dinosaurs to neanderthals. Now, something is threatening the existence of all timelines, dragging multiple different people and species into the struggle, among those a pair of cryptid hunting girlfriends and a transgender scientist.

Children of Time by Adrian Tchaikovsky*

Millenia and generation spanning scifi. After the collapse of an empire, a planet once part of a project to uplift other species to sentience is left to develop on its own, resulting not in the intelligent monkeys once intended but in sentient giant spiders. Millenia later, what remains of humanity arrives looking for a new home, only to be met by the artificial remains of the ancient woman who once led the uplift project - and she is not willing to let them on her planet.

Semiosis (Semiosis duology) by Sue Burke

A generational story following a group of humans trying to survive on a new planet, where a strange and unkowable intelligence is finding ways to use them to its whims. As the humans come across an abandoned city wrapped in the roots of a strange plant, they slowly come to the realization that mutual communication is the only path to peace and survival.

The Three-Body Problem by Cixin Liu

While I felt the characters could’ve been better developed, this is undeniably a well-written novel featuring an alien race and culture developed on a planet vastly different from ours. Firmly in the realm of hard scifi, this is a realistic, fascinating and slightly terrifying look at how first contact may look.

Brain Plague (The Elysium Cycle) by Joan Sloncewski*

Chrys, a struggling artist, agrees to become a carrier for a sentient strain of microbes. With their help, Chrys breathes new life into her career. But every microbe society is different - some function as friends and brain enhancers to their carrier, while others become a literal brain plague, a living addiction taking over the life of their carrier. And like every society, the microbe community is in constant flux - inluding the one inside Chrys's head.

Rosewater (The Wormwood trilogy) by Tade Thompson

In Nigeria lies Rosewater, a city bordering on a strange, alien biodome. Its motives are unknown, but it’s having an undeniable effect on the surrounding life. Kaaro, former criminal and current psychic agent for the government, is one of the people changed by it. When other psychics like him begin getting killed, Kaaro must take it upon himself to find out the truth about the biodome and its intentions.

Dawn (Xenogenesis trilogy) by Octavia E. Butler*

After a devestating war leaves humanity on the brink of extinction, survivor Lilith finds herself waking up naked and alone in a strange room. She’s been rescued by the Oankali, who have arrived just in time to save the human race. But there’s a price to survival, and it might be humanity itself. Absolutely fucked up I love it I once had to drop the book mid read to stare at the ceiling and exclaim in horror at what was going on.

Blindsight by Peter Watts*

Vampires and aliens and questions of the nature of consciousnesses, oh my. A ship is sent to investigate the sudden appearance of an alien vessel at the edge of the solar system, but the crew, a group of various level of transhumanism, isn’t prepared for the horrors awaiting them. No, seriously, this book will fuck you up, highly recommend if you’re okay with a lot of techno babble and existential horror.

Midnight Robber by Nalo Hopkinson*

Utterly unique in world-building, story, and prose, Midnight Robber follows young Tan-Tan and her father, inhabitants of the Carribean-colonized planet of Toussaint. When her father commits a terrible crime, he’s exiled to a parallel version of the same planet, home to strange aliens and other human exiles. Tan-Tan, not wanting to lose her father, follows with him. Trapped on this new planet, he becomes her worst nightmare. Enter this book with caution, as it contains graphic child sexual abuse.

Fragment (Fragment duology) by Warren Fahy*

The reality TV show Sealife is having a rough time - as it turns out, a ship full of scientist doesn’t make for the kind of drama they hoped for. Hoping for some excitement, they reach Hender's Island, a fragment of a lost continent that may contain an interesting new ecosystem. But as they step foot on the island, they quickly come to realize the ecosystem isn’t just new, it’s highly dangerous and very hungry. Among all this life is one single species that may be more dangerous than any other, but which may also be the salvation of the scientists on the island. A bit wonky, but genuinely one of the most fun books I have read, I love it so much.

Axiom's End (Noumena trilogy) by Lindsay Ellis

It’s 2007, and a leak has just confirmed that the US has reached alien contact. Cora wants nothing to do with it, but as her absent father is the whistleblower who dropped the news the media won’t leave her alone. Even worse, she soon finds herself meeting and being pursued by the alien presence itself as it tries to remain in hiding - and discovering that there is a much larger threat on the horizon.

The Road to Roswell by Connie Willis*

Francie has just traveled to Roswell to attend her college friend's wedding to a UFO conspirasist. Not a believer herself, Francie is shocked when she finds herself abducted by an alien. Her abductor is not much what popular media would have you believe, looking more like a tumbleweed than a grey alien, and is clearly on some kind of mission it isn’t willing to put on hold for the sake of Francie attending to her duties as a bridesmaid. As more people get roped along - among those a conman, an old lady, a ufo conspirasist, and a retiree with an RV - Francie finds herself getting closer to the alien and wanting to help it succeed.

Bonus rec: if you like this book, you may also enjoy the movie Paul, which has a similarly humorous tone and similar plot.

Project Hail Mary by Andy Weir*

Ryland Grace just woke up up from a coma, unable to remember anything. He finds himself alone on a space ship, and as his memories slowly trickle back, he realizes he's been sent on a mission: to find a solution to the impending doom of the earth. Still struggling with holes in his memories, Ryland tries to fulfill his mission, but as he gets closer to his goal, he discovers someone else got there first. And they aren't anything close to human. Funny, heartfelt, and heavy on the science.

Survival by Julie E. Czerneda

Mac, a biologist studying salmon on Earth, has little interest in life beyond her own planet. Despite this, she’s sought out by Brymn, an alien archaeologist hoping her expertise as a biologist can help him solve the secret behind the Chasm, a region of space completely devoid of life. Trying as she might not to get incolved, Mac has little choice as she and her colleagues come under attack by the mysterious Ro, the species Brymn's people suspect to be the cause of the Chasm.

Translation State by Ann Leckie*

An exploration of the alien as filtered through the human. At what point does the human become something else? When does something else become human? Is it a question of biology or culture, nature or nurture? Can we choose it? Can it be forced upon us? Set in the Imperial Radch universe, Translation State follows three different characters embroiled in the question of what makes a human. The alien Presger can only communicate with humans using their translators - people they’ve created that are not quite human and not quite alien. But as news of a translator fugitive arises, conflict brews regarding what right they have to choose their own identity and home.

Exo (Exo duology) by Fonda Lee*

Young adult. Earth has long since been under the control of an alien presence. Donovan Reyes is an exo, a human enhanced with alien technology, working to keep the colony and its people safe. The biggest enemy is Sapience, a terrorist organisation opposing alien rule by any means necessary. When a mission goes awry, Donovan finds himself abducted by Sapiance, something that risks a war. While it took until the second book for me to be fully sold on this series, it features a genuinely nuanced take on oppression and resistance rarely seen in YA genre.

Needle by Hal Clement

1950s classic. A small island in the pacific ocean and a fourteen-year-old boy have just become the center of an interstellar chase between an alien Hunter and the criminal he's pursuing. Robert is a regular boy, but he has a very special passenger: an alien symbiont hiding inside his body. The alien became stranded on Earth as he pursued a criminal of his own species, and now they are both trapped on the same island, playing a game of cat and mouse as Robert and the Hunter struggle to find their prey before it finds them.

The Long Way to a Small, Angry Planet (Wayfarers series) by Becky Chambers

Rosemary Harper just got a job on the motley crew of the Wayfarer, a spaceship that works with tunneling new wormholes through space. With a past she wants to leave behind, Rosemary is happy to travel the far reaches of the universe with the chaotic crew, but when they land the job of a life time, things suddenly get a lot more dangerous. A bit of a tumblr classic in its day, this is a cozy space opera with an episodic feel and vividly realized characters and cultures.

Under the Skin by Michel Faber

A dark allegory of alienation and dehumanization, Under the Skin follows Isserley, a woman traveling along the roads of England and picking up hitchhikers. Little does her passengers know, she’s an alien hiding her true self, and they are her prey and a delicacy for her species.

Solaris by Stanislaw Lem

1960s Polish classic. Arriving on a station orbiting the planet Solaris, Kris Kelvin is meant to study the strange, possibly sentient ocean that covers its entire surface. But the effects of the ocean are far reaching - Kelvin finds the crew of the station secretive and unstable, and is shocked to wake one day to the embodiement of a long dead lover. Was it created by the brain-like ocean, and if so, why?

West of Eden (West of Eden trilogy) by Harry Harrison

65 million years ago, the meteor that killed the dinosaurs never arrived. Without it, the dinosaurs lived and thrived, allowing a the complex society of the matriarchal Yilanè to arise. Meanwhile, in the new world, humans still evolve, and when an impending ice age forces the Yilanè across the ocean in search for a new home, the two are destined to clash. A bleak story of the cycle of violence and hate leading to war, West of Eden is a marvel of world-building.

Bonus AKA I haven't read these yet but they seem really cool

Triptych by J.M. Frey

Kalp is a widower and alien refugee newly arrived on Earth; Gwen is a language expert secretly recruited by the United Nations to help integrate a ship of alien refugees; Basil is an engineer who loves them both. Together they must defend their relationship against a violently intolerant world.

The Sparrow (The Sparrow duology) by Mary Doria Russell

When proof of alien life is found, the United Nations are too slow in their plans for a first contact mission. Instead, the Society of Jesus overtake them and send their own ship, but the crew could never have been prepared for what they will find.

Lagoon by Nnedi Okorafor

Something massive and alien crashes into the ocean off the coast of Nigeria. Three people, a marine biologist, a rapper, and a soldier, find themselves encountering this presence, and have to race to save humanity before it's too late.