A lot of what has been mentioned is well, useless. Sci fi seems to be dead unless you go online and delve into certain aspects of literature that sadly have passed on.
The greatest flurry of writing in th elast 20 years was anthro fiction. But that's basically dead online. Just a lot of ghost server websites left and a few mirror websites that have dead links to some of the greatest writing in the last 30 years.
I've never been called nobody before. Neverness was good, but his Magnum Opus was the Requiem for Homo Sapiens trilogy that followed Neverness.
I always wanted him to go back and write Kalinda's story. Instead he wrote the Lord of Light series, which essentially took the same characters (with different names) from Requiem and dropped them into a fantasy setting.
Tim Akers "The Horns of Ruin" is remarkably good in the steam punk genre. The main character is the last Paladin of a dead god.
The cover is one of the best I've seen on a book.
"Dune" by Frank Herbert is essential reading as well.
"Red Thunder" and it's sequels are excellent Sci-Fi, kind of a modern Skylark of space kind of series, but more grounded in reality.
Echoes the "home built spaceship with a unique and incredibly powerful power source" theme.
So many good authors / books mentioned in this thread.
My default answer to the question was posted by @ChopperHarris back in 2012 - that being Stand on Zanzibar by one of my favourite authors, John Brunner.
My contribution thus: for an easy imaginative and violent read are the works of Neal Asher https://www.goodreads.com/author/show/56353.Neal_Asher
The house on the borderland, William Hope Hodgeson is what I'm on at the mo. I was listening to 4 extra driving to work this week and caught this really spooky science fiction/horror story. Turns out it's free on Kindle
Pretty much all the stuff that's been mentioned, I love culture and big space stuff.
I'll second the Hamilton stuff, I like great north road. And the void series.
Margaret Atwoods day of the flood. And the follow up.
Russel Hobans Ridley Walker - if you can get of over the language (it's a bit marmite) - I loved.
I'd recommend the Old Man's War series by John Scalzi, although I got completely derailed by the fourth book being the third book but from a different perspective. I need to finish that book so I can continue on with the series.