You might check Radix by A.A. Attanasio. I classify it as sci-fi, it's on a post apocalyptic world, and the protagonist encounters alien creatures.
The book is old, from the 80s, and not really talked about, but it's definitely worth a look. Attanasio's later novels tho, I'd advise to stay clear off unless you like weird new-age stuff.
Another great novel from the 80s would be Armor by John Steakley, one of the best reads about powered armor like in Starship Troopers, or Ringo's Posleen series and the like.
If you haven't already you could try anything by C.J. Cherryh, they mostly fit your requirements and are great sci-fi. I'd suggest her Faded Sun trilogy which is one of my favorites. You could also check her Foreigner series which is still running.
Do you have an account on goodreads or somewhere ? I have a lot of other suggestions but it's kinda hard without knowing what you've already read.
Only one recomendation for you.
Old Man's War by John Scalzi
https://www.goodreads.com/book/show/51964.Old_Man_s_War
I love this series, why?
This is how the book starts: "John Perry did two things on his 75th birthday. First he visited his wife's grave. Then he joined the army."
I know what you are thinking, i said young guys not old dudes, but what if the army wants old people experience and wise minds to put them in young strong genetically modified bodies?
Hope you enjoy it
Old Man's War by John Scalzi
https://www.goodreads.com/book/show/51964.Old_Man_s_War
I love this series, why?
This is how the book starts: "John Perry did two things on his 75th birthday. First he visited his wife's grave. Then he joined the army."
I know what you are thinking, i said young guys not old dudes, but what if the army wants old people experience and wise minds to put them in young strong genetically modified bodies?
Hope you enjoy it
Something similar to Siege of Titan (Star Crusades Uprising #1) by Michael G. Thomas, mostly indie military sci-fi :
* Poor Man's Fight by Elliott Kay
* Forging Zero (The Legend of ZERO #1) by Sara King
* Marines (Crimson Worlds #1) by Jay Allan
* Terms of Enlistment (Frontlines #1) by Marko Kloos
Similar to Nathan Lowell - Solar Clipper Trader Tales. Kinda hard but here are a few recs, mainly coming of age stories with a sci-fi setting, but without being space operas, space battles, and such :
* A lot of Heinlein's Juveniles have the same feel as Nathan Lowell's series, like Farmer in the Sky, The Rolling Stones, or Have Space Suit—Will Travel
* Take the Star Road (The Maxwell Saga #1) by Peter Grant
Not coming of age stories, here are more recs that focus on "normal" activities (rather than soldier, spy, or whatever) but in a sci-fi setting:
* The Rookie (Galactic Football League #1) by Scott Sigler
* Hospital Station (Sector General, #1) by James White
* Stardoc (Stardoc #1) by S.L. Viehl
* Poor Man's Fight by Elliott Kay
* Forging Zero (The Legend of ZERO #1) by Sara King
* Marines (Crimson Worlds #1) by Jay Allan
* Terms of Enlistment (Frontlines #1) by Marko Kloos
Similar to Nathan Lowell - Solar Clipper Trader Tales. Kinda hard but here are a few recs, mainly coming of age stories with a sci-fi setting, but without being space operas, space battles, and such :
* A lot of Heinlein's Juveniles have the same feel as Nathan Lowell's series, like Farmer in the Sky, The Rolling Stones, or Have Space Suit—Will Travel
* Take the Star Road (The Maxwell Saga #1) by Peter Grant
Not coming of age stories, here are more recs that focus on "normal" activities (rather than soldier, spy, or whatever) but in a sci-fi setting:
* The Rookie (Galactic Football League #1) by Scott Sigler
* Hospital Station (Sector General, #1) by James White
* Stardoc (Stardoc #1) by S.L. Viehl
When I made the mistake of getting into GoT (hate starting a series before it's complete so I have to wait for the next book), I went scrounging for other goodies to fill the gap. Found several that are written way, way better than Martin and with way better world-building. Not sure if you include sword & sorcery/fantasy, but that's what I've got.
Top of my list here would be The Cycle of Arawn series by Edward Robertson. Unusual to me because it's written from the perspective of a male character (and his buddy) and is full of snarky répartée and testosterone, but it's also a really great fantasy story with lots of magic and fighting. Three books in all (The White Tree, The Great Rift, and The Black Star).
Did anyone mention Robin Hobb? The Farseer Trilogy is mainly from a male perspective and those 3 books lead you into The Tawny Man series (also 3 books). From there, you can branch into the Liveship Traders. Having read everything she's written (even as Megan Lindholm), I can't recommend her Soldier Son series at all. Ugh. Such a long, painful slog for an infuriating ending. Definitely a guy book, just not fun at all.
I assume The Wheel of Time series isn't a stranger to anyone. It does bog down in the middle somewhere, but if you're into long series (15?), it'll keep you busy a while.
Sadly, even after all these dozens of books and several other series as well, I'm still waiting on the next GoT. At this rate, George is going to drop dead and someone else will have to finish for us. That actually worked well for WoT because Brandon Sanderson not only wrote the last two books sounding just like Robert Jordan, but I think he did a much tighter job of it.
Top of my list here would be The Cycle of Arawn series by Edward Robertson. Unusual to me because it's written from the perspective of a male character (and his buddy) and is full of snarky répartée and testosterone, but it's also a really great fantasy story with lots of magic and fighting. Three books in all (The White Tree, The Great Rift, and The Black Star).
Did anyone mention Robin Hobb? The Farseer Trilogy is mainly from a male perspective and those 3 books lead you into The Tawny Man series (also 3 books). From there, you can branch into the Liveship Traders. Having read everything she's written (even as Megan Lindholm), I can't recommend her Soldier Son series at all. Ugh. Such a long, painful slog for an infuriating ending. Definitely a guy book, just not fun at all.
I assume The Wheel of Time series isn't a stranger to anyone. It does bog down in the middle somewhere, but if you're into long series (15?), it'll keep you busy a while.
Sadly, even after all these dozens of books and several other series as well, I'm still waiting on the next GoT. At this rate, George is going to drop dead and someone else will have to finish for us. That actually worked well for WoT because Brandon Sanderson not only wrote the last two books sounding just like Robert Jordan, but I think he did a much tighter job of it.
More sugar!