I highly recommend anything by Adrian Tchaikovsky. His themes and ideas are deep and fascinating. https://www.amazon.com/stores/Adrian-Tchaikovsky/author/B002... (Children of Time Series, Dogs of War and City of Last Chances are great). Him and Dan Simmons are my favorite new(ish) authors. If you haven't read the Hyperion quadrilogy, it's my favorite sci-fi series ever.
I hate to be that guy, but I find Andy Weir's books to be very simple and 'light' sci-fi. Fun reads but usually suffers from the protagonist being a genius and smart aleck. No deep themes or characters. I never understood the crazy appeal after reading all of Asimov and Arthur C Clarke. Personally I want giant themes, huge space operas, complex characters and long storylines!
I agree with your take that Andy Weir's writing can feel a bit lacking - at least in the Martian. But I was willing to give him a bit of a pass based on how the story was originally self-published in serial form. My hope is that Project Hail Mary will be a bit more refined - but even if it reads just like the Martian, I am definitely interested to give it a read.
The Red Rising series is also very good.
So my hope is that as I keep growing this every year that we get a very wide selection even if a lot of classics also popup :).
On the plus side, this is the first I am learning of Project Hail Mary, and definitely plan to give it a read. Thank you for compiling this list!