It’s not old, but may I recommend The Expanse series by James SA. Corey? It’s excellent science fiction military space opera. I fell in love with the TV series but the books are fantastic in their own right. The first book is space noir. And that’s really cool! A huge cast of great characters, fascinating political landscape (including an asteroid belt culture with its own pidgin language) and a protagonist you can truly root for.
If you’re into whacked out fantasy/horror I rec T. Kingfisher. She retells a lot of fairy tales, but her Saint of Steel books are the best, she’s really built her world and her people, and her spin on religion is fabulous.
I was a BIG fan of Tanith Lee in my 20s. Her books are dark, atmospheric and stark reminders that two people don’t always see “morality” in the same light.
And I’ll second the Murderbot Diaries. Very soap opera, if the bromance between a semi organic construct and a bot pilot sounds good, do dive in! But it’s also adventuer and corporate espionage as well. And hunt up the short filler stuff between the books, most of it is online for free.
Something else that I wanted to share. Long and complicated story, but to summarize I have had some surgeries and then meds that severely affected my memory and other abilities. I picked up reading again full blast after coming home from a trachectomy that came very close to ending my life (Spell checker is trying to change it to Tracheology, but isn’t that a medical field, not a procedure?). I’ve read about 40-50 books this year so far, both old favs and new material. I feel that reading has helped my mental recovery and logic skills considerably. It is an exercise for your brain, and I am so happy that I’ve been able to pick it back up again. And again, thank you so much, Dopers, for helping me find new things and broadening my horizons.
“My books are all doors to other worlds. Worlds in which I can find myself, lose myself, or both”: Me
I’ve been meaning to read Piranesi. But until I do, I’ll recommend Clarke’s first novel Jonathan Strange & Mr Norrell.
If you like classic SF, and if you haven’t read Ursula Le Guin, you gotta read her! She is, in my opinion, the best American author of the twentieth century, and the best sff author who’s ever lived. She’s brilliant and wise and witty, and her prose flows like clear mountain water. Left Hand of Darkness, of course, but also The Dispossessed to see how political stories can be written without wagging a finger in the reader’s face.
If you want something more modern, NK Jemisin’s Broken Earth trilogy is a tour de goddamned force. It’s the only time any author has won the Hugo for three consecutive years, and well-deserved. This is fantasy that will knock you on your ass, so rich and layered and brutal and gorgeous.
And if you want something delightful, Susanna Clarke’s Jonathan Strange and Mr. Norrell is delightful.
In terms of more recent works, I have two I’ll recommend:
Alien Clay, by Adrien Tchaikovsky. I love his science fiction, and this is my favorite: a political dissident is sentence to hard labor on a hostile alien world, and the book is a mix of xeno-ecology and political irony in the best possible way. I had so much fun with it.
The Daughters’ War, by Christopher Buehlman. Normally I’m not a fan of military fantasy, but this is done right. The protagonist’s voice is strong and compelling, the villains are simply the worst, and there are fucking war covids. It’s got big horror energy, but also made me burst into giggles at least twice.
Henry Miller’s auto-bio books, the Tropics and the Rosy Crucifixion, are fun.
I recommend Clifford Simak’s stuff. He’s an early SciFi writer, from the 1950s-60s. His 9 stories-on-a-theme episodic book, City won awards, but I like Waystation and a lot of his short stories better. He’s a gentle writer who is more interested in coexisting with the aliens than conquest. Some of his ideas about that are charming … and creatively mischievous. Two favorites are Leg. Forst about an intergalactic stamp collector and Desertion about humans colonizing Jupiter.
If anyone is as confused by this as I was, I looked up a review of the book and LHOD left out an R in the third word here.
If you like Borges, I recommend Italo Calvino – especially Cosmicomics.
Looking at the list I think Margaret Atwood’s “Maddaddam” series would be a good fit in terms of dystopian future themes. Claire North is a young British writer who explores some weird themes - “84K” and “the first fifteen lives of Harry August” are worth checking out.
If you’re looking for something light and weird, Jasper Fforde is worth a look
Oh, good Lord. Thank you for the catch! War covids are infinitely less badass than war corvids.
Margaret Atwood’s name sounds familiar to me, but I can’t quite place it. Did she write dungeons and dragons books?
My wife has read this thread and informed me she has an old Jane Austen book titled Three Great Novels. Found it, and it has Sense and Sensibility, Pride and Prejudice, and Emma. So that’s a pleasant surprise!
Atwood: The Handmaid’s Tale, Oryx and Crake.
I’m not sure whether I would freaking love to play in a Margaret Atwood D&D module, or whether it would be pure distilled hell, or both.
I read Exordia based on a recommendation by @Left_Hand_of_Dorkness in an older thread and loved it.
I’ve recently discovered a trove of newer authors who are still writing, whose books i seek out (mostly from the library) when they are published. This is not a complete list, but it’s who comes to mind. Some have been mentioned above:
Martha Wells (her older books have some issues, but are incredibly creative. I enjoyed the raksura books, and i think they were indirectly the precursor to the murderbot books, as she realized both some of the mistakes she made and investigated the logical consequences of some of her characters.)
T Kingfisher, who also writes (mostly children/ya stuff) as Ursula Vernon. Quite a lot of variety in her works, from realistic horror to romance novels set in a really cool and well-developed fantasy world to rewrites of fairy tales.
David Lavine (mostly YA stuff, i think) fun, light “teens on Mars”. And other series.
Naomi Novik also quite a lot of variety. She has a whole series of “Horatio Hornblower with dragons”, some very atmospheric takes on fairy tales, and a “magic in the modern world” series (scholomance) that i think it’s super.
Ann Lecke: have you ever wondered what it would feel like to be a rock that has become a god? She has, and she’ll share that with you. Also some stories set in an interesting future stellar empire. Really good world building.
Samantha Shannon: do you crave a huge complicated world, with nations that view the same history from different perspectives? With characters who are flawed but interesting? These are long, but i enjoyed them.
Bujold (getting towards the end of her career) i like the 5 Gods world even more than the stories about Miles.
Ted Chiang (older) really interesting mathematical fiction
Greg Egan (maybe done writing) my favorite author for years, but i like his shirt stories more than his novels, personally.
Oh, and two more that i found this summer, when i bought the Hugo nomination packet:
Robert Jackson Bennett: stories with interesting characters set in a week developed and interesting world
Nghi Vo: my two favorite stories among this year’s Hugo nomination were written by the same author. And her stuff is sold in non-DRM epub books! I bought a whole lot of her works. I’m in the middle of one, now. Mostly, I’ve read stories about a monk who travels the world (vaguely medieval China, with magic) to collect stories. But I’m directly reading a story about a demon who loved and nurtured a city.
The Hugo nomination packet is a great deal, by the way, especially if you are looking for new-to-you authors. For about $50 (technically, i bought remote membership and the right to vote) you get samples, usually complete, of everything nominated for the Hugo awards this year. It’s a ton of material (whole series were included this year, which i haven’t touched, yet) all of which is good enough to earn a Hugo nomination.
Neil Gaiman’s “The Sandman”, though a graphic novel, has some of the finest writing in the fantasy genre, winner of a Hugo Nebula Award and 26 Eisners. Well worth a look 
I’ll second Gryphea’s recommendation of *The First Fifteen Lives of Harry August”. I recently read a book with a somewhat similar concept, of a girl who is born early in the 20th century and keeps dying and being reborn. In her first life she dies almost immediately, because her umbilical cord is wrapped around her neck fortunately for her – and for the story – that is corrected in later lives. In one life she becomes a good friend of Eva Braun, and in another she tries to kill Hitler before he becomes Chancellor. Unfortunately, I can remember neither the book’s title nor the author’s name, but I believe it’s a new book that just came out this year. (@Andy_L?)
There’s also Replay, by Ken Grimwood – came out in the '80s, so it may be hard to find a copy. It is also about a guy who keeps reliving variations on his life (though he starts by dying in the '80s and waking up to find himself in his dorm room in 1963).
The first book was a good read, but I didn’t read any of its sequels. Couldn’t get past the basic concept that dragons existed and had been used in warfare for centuries, but had had so little effect on history that in the early 1800s England was still worried about the possibility of invasion by Napoleon.
I enjoyed the dragon series, but i think it’s among her weaker work. If you enjoyed her pacing, characters, etc., try some of the others.