No love for Iain M Banks? The Culture series looks like it will tick all your boxes and instead of following a single protagonist the Culture itself is the protagonist so each book has it’s own cast of interesting characters.

John Scalzi's Old Man's War series was a long and pretty interesting read.

Premise starts out as a "humanity vs the stars" kind of story, but instead of sending young people to their deaths, the futuristic human society instead recruits old people who have already lived full lives. You can enlist towards the end of your natural life to transfer your mind to a (photo)synthetic purpose-built humanoid super soldier body. If you survive a period of time (5 years?), you earn another shot at life and can elect to become a colonist for far away worlds. Most don't get that far. Your usual "long-term relationship tensions," "humans are always bad guys," "what will technology think of next?" tropes apply.

Another series I liked is the Castle Federation series by Glynn Stewart.

This series spans a much shorter timeframe throughout its books but contains much more civil-war type political intrigue and seems to focus more on an important battle or two per book. As such, you get a more granular view of one starship officers experiences from the unit level up to the fleet. Tactics, deception, and an almost constant state of Pyrrhic victories help to make you feel like you aren’t simply following around a grand hero figure who is the unspoken savior of the galaxy. I don’t really remember how the series starts, but it’s mostly (or all) human-vs-human conflicts.

Last series I enjoyed is the Frontlines storyline by Marko Kloos.

In contrast to the stories above, it’s humans (mostly) good, aliens bad. A dystopian future is rocked by the sudden appearance of monolithic and seemingly invincible stegosaurus-like alien beings. They show up, terraform your world with CO2, and brush off humanity like we’re ants. You follow a few main characters who give you insight to how the big governments operate, how soldiers are thrown into unwinnable conflicts, and how freedom fighters back home protest against the majority of humanity’s production efforts going towards war while ignoring the problems at home. There’s a good mix of hopeless alien combat, human conflict and frustration towards the military industrial complex, Judge Dredd-like slums, and some anthropology thrown into the mix. Facing an existential threat, would you throw everything at offense and let your people starve?

Alastair Reynolds - Revelation space i.e. Inhibitor sequence

Peter F Hamilton - Void trilogy in the Commonwealth universe

Pandora’s Star and the sequel Judas Unchained by Peter F Hamilton

Have you read Hannu Rajaniemis Jean le Flambeur series?

It’s a very high concept narrative, that begins with our main character being broken out of a simulated prison, where he is forced to play endless games of the prisoners dilemma, against endless copies of himself and other prisoners.

It continues on to tell a story set within our solar system, that’s complex on levels that can be hard to keep up with at times.

In this universe, where people end and software begins, is blurred, and the same is true for the edge between reality and simulation.

Some people are doomed to exist and be used as mere software for completing complex tasks, while others step through matter-conversion gates between the real and simulated on a regular basis.

I really, really loved it.

You could try Altered Carbon by Richard K Morgan. It's the first book in the trilogy. The book was better then the Netflix series.

Starship Trooper

The Three Body problem is a an absolutely phenomenal take on the Dark Forest Theory.

It has the unfortunate quality of reading like a news article at times, recounting events, rather than feeling like an illustrated narrative. And some plot points hinge on the authors pre-conceived notions about gender that really didn’t sit well with me.

Off the top of my head, here’s a few:

• The Commonwealth Saga, by Peter F Hamilton

• Hyperion Cantos

• The Spiral Wars

Ooh, another operatic that comes to mind: 2312 by Kim Stanley Robinson