Red Rising by Pierce Brown. You seem to like a lot of the same books I do. I just found this series and I loved it.

Alright, we’ve got some overlap here, let’s see…

• The Red Rising Saga. I’m working through book 6 right now as an audiobook and I’m sneaking in a few minutes wherever I can. Definitely expands its scope as the series goes on and while I feel like I’m losing context for some of the new/returning characters at this point, I can follow enough to go along with it. The main character is born into the lowest caste of the society and works to infiltrate the highest caste. It’s a long ride and ebbs and flows from hopelessness to triumph throughout the course of it.
• The Combat Codes Saga. Probably closer to science-fantasy then fiction, but an interesting idea about nations using hand-to-hand combat to settle wars, territory, etc…I have only read the first book so far but I enjoyed it a lot.
• Alex Benedict - I would encourage this more as a filler or inbetween books series. Binging all of the books can make them feel very samey. The core idea is that all of the books except the first one are told from the perspective of a colleague/assistant/“jill of all trades” woman who works with one of the most famous artifact hunters in the far future. Each book is essentially chasing an archeological mystery of some sort.
• The Jubilee Cycle - I found the first book a long time ago at random in one of those discount bookstores and picked it up based on the cover alone. It’s about a future where everything you do costs you money, to the point where political parties debate whether or not autonomic functions like breathing should cost money. The prose is a little dry and the author works as a translator, but I enjoyed the world that he built up as the main character peels back the layers of this society after he gets essentially bankrupted by a mysterious and unknown transaction.
• Teixcalaan - Can’t link the series for some reason. The main character is an ambassador to the ruling empire of the galaxy, trying to figure out who killed her predecessor and a conspiracy surrounding him. It felt very dense when I started it but I enjoyed it a lot!

You’ve already had a recommondation for most of what I would suggest to you, but I will happily second the suggestions for the Revelation Space series by Alastair Reynolds, the Teixcalaan series by Arkady Martine, and the Imperial Raadch/Ancillary series by Ann Leckie. All have excellent worldbuilding and tell stories that depend heavily upon how their characters interface with the worlds they inhabit.

A little pulpier in tone, but still very well put together, I’d suggest as well the Wayfarers series by Becky Chambers, and especially the Locked Tomb series by Tamsyn Muir. The latter is a bit more fantastic space opera as opposed to some of the harder sci-fi you’ve mentioned, but Muir knows how to write a setting that is absolutely dripping in gothic horror, and still take you on an emotional roller coaster fully of highs, lows, and humor as you read it. It seems to be a bit of a love-it-or-hate-it series from the other conversations I’ve had about it, but I love it and I’d be remiss not to suggest it.

I’d also suggest, if you’re not averse, dipping your toe into the fantasy genre as well. There’s a broad range of authors there who have done excellent work building fantasy worlds that are structurally deep and compelling, and have many science-fictional qualities. Along these lines I’d suggest Robert Jackson Bennett’s Founders trilogy, or N. K. Jemison’s Broken Earth trilogy – though, fair warning, both of these broke me in the end emotionally. Worth it, though!

Have you tried CJ Cherryh, particularly the Alliance-Union universe? If you’d like to start with a longer novel, I’d suggest Downbelow Station or perhaps Cyteen (though DS is one of my favorites) if you’d like a faster and less deep introduction, I’d suggest Merchanter’s Luck or The Pride of Chanur.

Iain M Banks’s Culture series; Consider Phlebas, for instance, or The Player of Games, seem to be pretty much what you’re asking for.

I’ve been plowing through Three Body Problem series by Cixin Liu recently and it’s been really great. I’m on the home stretch of the last book and so excited to finish it.

All about space exploration, first contact, invasion, advancement and philosophy. A really great thinking book and leaves me with lots of uncomfortable feelings to ponder over. The pacing of the book took a little bit to get used to but it does well to help grapple with the time and space scale it is working with.

You’ve got some moderately highbrow and transhumanist stuff in there; have you tried Greg Egan? The two starting places I like to recommend are the Clockwork Rocket books (natives of a universe with alternate physics explore it and figure out what’s going on, kind of Flatland turned up to 11… and then up to 121…), and Permutation City which I think will meet your “some very interesting ideas” and then keep accelerating.

Recently: a friend bugged me until I finally got around to Red Rising

I haven’t actually read the series, because it’s heavy and I wanted to let it breathe a little. It’s dark, and the first one has kind of a feudal setting for most of the book I can’t explain without spoiling it, but it’s a ride. I always listen to audiobooks at 2x and had to go back and listen to the closing song at regular speed to get the full impact of the emotion.

Here are a few more…

“True Names” by Vernor Vinge (1981)

• Themes: Hackers, NSA, Privacy concerns, VR, social network, “true death" is what we call “doxxing” today.

“Daemon” [Series] by Daniel Suarez (2006,2010)

• Themes: Artificial Intelligence runs amock.

“Children of the New World” by Alexander Weinstein (2016)

• Themes: Social Media, VR, robotics, dependance on technology.

“Cumulus” by Eliot Peper (2016)

• Themes: Tech giant (Social Network) with too much power.

I haven’t read a lot of science fiction recently, but if you like adventure and world building, then March Upcountry is a great read. The books are short, but it’s a series, so all together it makes up a thick book. :)

Another vote for Cherryh - pretty much anything by Cherryh. And in the “journey” department, perhaps also look at John Varley’s Gaia trilogy (Titan, Wizard, Demon)? (Probably falls into your “excessive violence and some smut” category)

You might also try the “far future/dying Earth” genre as a way of getting the exploration without necessarily being tied to the space/hard sf milieu. I think the most awarded member of this subgenre (and I liked it quite a bit) is Gene Wolfe’s three Sun series (Book of the New Sun, Book of the Long Sun, Book of the Short Sun).

C.J. Cherryh’s Foreigner series spans 22 volumes (currently). I enjoyed it immensely.

While not sci-fi, Patrick O’Brian’s Aubrey-Maturin series is great for “on a journey” across the seas of the Napoleonic era.

Terra Ignota series by Ada Palmer. Interesting world where people choose their nationality and legal structure independent of physical borders.

Frank Herberts ‘WorShip’ trilogy is one of my personal favorites after Dune. Although the first book in the series, ‘Destination: Void’ is a hard slow burn.

All the 3 books can be read as individuel stories, but just give a “bigger picture” if read as a series.

There’s also something to be said about some of the more ‘Classic’ Sci-Fi books, like: ‘Starship Troopers’, Do Androids Dream…’ and ‘2001’.

‘Annihilation’ is another really good book. I haven’t read the sequels yet, so I can’t speak on those.

‘The Void’ trilogy by Peter F. Hamilton is another series that might interest you. It’s sci-fi with a hard ‘S’ if remember correctly.

Peter F. Hamilton’s books may fit the bill: Futuristic, not hopeless/dystopic, and the main characters tend to make reasonable decisions. Be wrned though that he favours deus ex machina conclusions. Most will suggest Pandora’s Star as a starting point (with good reason, as the Commonwealth Saga is quite expansive), but it does not have to be. I personally read the Night’s Dawn trilogy first. The Salvation trilogy also stands on its own, and for a completely standalone book Great North Road was a good read.

Adrian Tchaikovsky is another wonderful author! the Children of Time and Final Architecture series were quite enjoyable.

Redemption Space (Alastair Reynolds) is another series one that I like to recommend. Closer to The Expanse. House of Suns also is a great read by the same author, as are several of his other stories.

The White Space books by Elizabeth Bear should be on your reading list.

Vorkosigan Saga (Lois McMaster Bujold) is a bit dated but similar to Vatta’s War in the earlier books. Later on the plot tends to be more along the lines of whodunnit mystery… in space.

And let’s not forget another scifi favourite, Iain M. Banks! The Culture series are great of course, but I liked The Algebraist the best.