Andy Weir - The Martian. Possibly the most well researched science fiction book I've ever read. Well worth reading even if you've seen the movie, since that leaves out about half the things that go wrong and the large majority of the technical details.

Andy Weir - Artemis. Weir managed to figure out a way for a city on the moon to make economic sense, while physics makes it almost impossible.

Neal Stephenson - Seveneves. First sentence: "The moon blew up without warning and for no apparent reason." What follows is the brutally, unforgivingly hard consequences.

Artemis was a poor showing. Felt like it was written by an angsty teenager. Full credit to The Martian, though.

I’ve read the first two but will certainly check out the third. I loved The Martian, but Artemis wasn’t my jam. Felt too far fetched to me.

Seveneves is great as are Snow Crash and Anathem by the same author. Anathem has a lovely epic feel. Tough read though!

I haven't read Anathem yet. Stephenson's Cryptonomicon and The Diamond Age are also excellent, but getting away from hard sci fi.

I've read The Martian in no time, I struggled with Artemis though

The Three-Body Problem by Cixin Liu, and the other two in the trilogy too. Hard, but accessible. I've never read a series so dense with cool and believable ideas that are unlike much I had come across before.

The Reality Dysfunction by Pete F. Hamilton (and the rest of the series). If you want something a bit more traditional in form. More sex, violence and so on.

Ach, loads of others. Roadside Picnic really stuck with me too. Though might not be what most people would call 'hard sci-fi', not sure.

Hamilton is great, but more space opera than hard sci fi. The Commonwealth Saga is amazing.

Yeah I guess that is true. I think in my mind 'hard sci-fi' is more of a trait than a sub genre. Actually now I think about I think maybe purist hard sci-fi fans might not be very big on Peter F. Hamilton. Greg Bear would have probably been a better bet for an extra recommendation!

Blindsight by Peter Watts. It's great at avoiding the "benevolent aliens that are basically just weird humans" concept that most other sci-fi books seen to enjoy.

I would recommend Collapsing Empire by Scalzi. Here is the blurb:

Our universe is ruled by physics and faster than light travel is not possible -- until the discovery of The Flow, an extra-dimensional field we can access at certain points in space-time that transport us to other worlds, around other stars.

Humanity flows away from Earth, into space, and in time forgets our home world and creates a new empire, the Interdependency, whose ethos requires that no one human outpost can survive without the others. It’s a hedge against interstellar war -- and a system of control for the rulers of the empire.

The Flow is eternal -- but it is not static. Just as a river changes course, The Flow changes as well, cutting off worlds from the rest of humanity. When it’s discovered that The Flow is moving, possibly cutting off all human worlds from faster than light travel forever, three individuals -- a scientist, a starship captain and the Empress of the Interdependency -- are in a race against time to discover what, if anything, can be salvaged from an interstellar empire on the brink of collapse.

Larry Niven - Ringworld (+ Ringworld Engineers), The long Arm of Gil Hamilton, Oath of Fealty (Oh man! They had instant messaging wetware! ...And a diving board!).

Robert Heinlein, Joe Haldeman, and Issac Asimov are some other heavy hitters in this space.

I immensely enjoyed Children of Time by Tchaikovsky, coincidentally winner of the 2016 Arthur C. Clarke award :)

So did I, but I wouldn't classify it as hard sci-fi. Too many things left unexplained for that.

If we consider Three Body Problem as hard sci-fi (see above), then Children of Time definitely clear that bar too.

Ian Banks - The Use of Weapons

The "culture" series of books was the first coherent portrayal of a non-dystopian advanced society with AIs that I encountered. It’s a reasonable “good” future.

Iain Banks is his mainstream work, Iain M Banks is the science fiction. It's fantastic, but far away from hard sci fi.

The Red Mars trilogy, by Kim Stanley Robinson. All of terraforming Mars in a hefty triple-tomed story that leaves naught unexplained.