Alright you shits, enough doomposting. Time for some literature. I've been on a sci fi wave recently, so I'm starting with this genre. Preferably post less well known works you think have value. It'd be nice if you include a little info about the books themselves. I'll start.
The Lost Fleet series and its sequel The Lost Fleet - Beyond The Frontier by Jack Campbell are a series of military sci fi. The series is set one-hundred-plus years into an interstellar war between two different human cultures. The protagonist of the story is discovered floating in a suspended animation escape pod one hundred years after he made a "heroic last stand" against an enemy fleet and is suddenly dropped into the role of fleet commander and expected to live up to the legend that has grown around him.
The books have probably the best take on space combat I've ever come across with things like relativistic time issues, comm lag and heavily automated systems due to the sheer speed of engagements. No Star Wars WWII bomber runs.
The characters are pretty well developed and likeable with a large focus of the books being on things like duty, honor and sacrifice. Very little, if any, cheap drama.
The protagonist is not perfect and makes mistakes. The beginning of the books might make him seem a bit like a Gary Stu due to being literally the only guy left alive who knows how to lead a battle in space properly (all the rest died over the century of fighting) but the people around him and his enemies learn from him over the course of the books and get better with each fight. The books are good fun and I can't recommend them enough.
The only downside is that the author isn't that great at writing. The prose is not terrible but I'd give him a 8/10 for plot, 10/10 for world-building and 7/10 for actual writing skills.
The sequel Beyond the Frontier has less fighting (though still plenty) and is more focused on exploration. This is also my favorite take on space exploration from all the books I've ever come across.
This is why you really need to distinguish the book from the movie. Heinlein called himself a libertarian but he was also in the military.
The entire theme of the book is willingness to sacrifice. The ships name , Roger Young, is named after a guy who sacrificed himself so his team could assault an enemy machine gun nest.
It's an "ask what you can do for your country, not what your country can do for you" idea.