Isn’t that the opposite of ‘hard’ science-fiction? Why did you specify “hard” if you aren’t interested in the actual science part? 
I recommend you peruse the Mohs Scale of Science Fiction Hardness. You’re bound to find something just right for you.
I’m thinking the “definitive work” shouldn’t feature renegade soldiers who all happen to be cannibals – and black. Niven and/or Pournelle may have been okay once upon a time, but definitely went off their rockers. I’d avoid.
Also, you can hardly read a Niven story without tripping over FTL, so not so much “hard” science.
If not-so-hard SciFi is okay, though, I’d go with CJ Cherryh – any of the Company Wars books (e.g., Downbelow Station); or the First Contact series (starting with Foreigner), Serpent’s Reach or Cuckoo’s Egg for aliens. Or Cyteen for fairly “hard” sci-fi that slants more toward the psychology/biology sciences (and still holds up fairly well).
Hard SF is defined by basis of how the world/universe works. That is, if the world/universe has basically the laws of physics that we know now, with one or a few advances, it’s hard SF. FTL is usually allowed because otherwise, we’d be stuck in one solar system and/or have generation or sleep starships.
John Varley’s Thunder books are hard SF, but the science is never really explained. Instead, Varley shows us what humans would probably do if we DID have this incredible science breakthrough. Similarly, in Scalzi’s Old Man’s War, the math and science of FTL travel is never explained. The only character in the book who understands it cheerfully tells the other characters who are curious about it that they don’t have the mathematics to understand it. And that’s OK. We (the readers) don’t need to understand how the FTL works, we just need to know that this universe HAS FTL, and humans can use it.
David Palmer had a great book, Emergence, that I really enjoyed. It had been serialized in Analog and then released as a PB. I read it in Analog, and then bought the book. I loved it. A couple of years ago, he sold the sequel to Analog, who again serialized it. It was a slog fest. Palmer felt the need to tell us how the heroine tweaked this or that control on her airplane, and the effect it had. I’m sure that this was fascinating for aircraft buffs, but it really didn’t move the story along at all. I ended up skimming about 2/3 of that story, because most of it was taken up with these trivial details.
A recommendation for David Brin.
Let me try to explain: I want a good story with plot development and interesting characters set in a ‘hard’ science fiction setting, where there are good justifications for FTL, weapon systems and whenever science is used as a plot element. I am, however, not interested in pages after pages on explaining on how a technology work, or why it works. I’m not looking for novels where the science takes up the bulk, like weapon technology in some Tom Clancy’s books or fashion in the Wheel of Time 
For the classics I’d go with some Clarke, maybe Rendezvous With Rama or Songs of Distant Earth. I came to severely dislike Heinlein in time, but he did have some good stuff. If you choose to go that route I’d recommend The Moon Is a Harsh Mistress or Starship Troopers. Be wary of seriously insane politics/economics/psychology. Asimov is actually my favorite of the big three but that’s because I’ve been a fan since youth; as literature I think his work is probably the worse of the lot, even if I love it the most. From him I think I’d go with The Caves of Steel or The Gods Themselves. Just to round this out, for the older stuff I’d also suggest Dune by Frank Herbert and The Mote in God’s Eye by Niven and Pournelle. Both are very good, but of the two I think *Dune *is by far the superior book, but both my father and sister disliked it profoundly. If you do read it, be sure to skip the sequels.
The two books I like to plug whenever I see a thread like this are Blindsight by Peter Watts and Ring of Swords by Eleanor Arnason. Both are recent and neither is very well-known, but they should be. Both books fully realize hard sf’s promise of being a literature of ideas, but manage to integrate those ideas with a kind of characterization and thematic and formal concerns which are much more usual in “literary” fiction than in science fiction.
Blindsight I actually read because I saw somebody else post about it here in the Dope. It’s a first contact story set in the relative near future. It’s deep, dense and not too long, which is a virtue more authors should master. It reads a bit like a modernist novel and Watts has some serious chops as a writer. The characterization is very unusual as none of the people you read about are quite human in the way we usually understand the concept. The book’s main concern is the nature of consciousness and its relation with intelligence, so each character is chosen to illustrate a different perspective on the problem, but always in a way that’s fully justified by the logic of the world of the novel and of the plot. The result’s probably the most thematically consistent science fiction novel ever. It’s philosophy heavy and features very hard science, but the weight of the ideas doesn’t get in the way of a great story which is essentially psychological in the end. It’s one of the very best sf books I’ve ever read and I think also one that best showcases all that sf aspires to be and do.
Ring of Swords doesn’t have a lot in common with Blindsight - it’s also one of the best sf novels I’ve read, but for completely different reasons. It’s not about philosophy and science but about diplomacy, anthropology, theater and romance. It reads much lighter than Blindsight but there’s still a lot of depth in the novel and if the prose is not showy or experimental at all, it’s of a quality very rarely seen in sf (which does tend to be either too plain or too overwrought in my opinion). The science is not the hardest, but other than faster than light travel there’s nothing there that could bother anyone and, again, the science isn’t the focus anyway. It’s also a first contact story and much more conventional on the surface. Neither the aliens nor the humans are as weird as on the other book. In fact, the aliens on this book, while still alien, are more human than the humans in Blindsight. The result is still very subversive: I’ve just spent 10 minutes trying to think how to describe the book’s plot and then gave up and went to amazon to see what they had there. Their summary is not only inaccurate and misleading, but also contains spoilers. It’s very hard to describe the book without either making it sound ridiculous or writing an essay about it. Just read it and see what you think.
Do not pass Go, do not collect $200. Go straight to your nearest bookstore and get Hyperion by Dan Simmons.
Ignore the shitty cover art. Truly a book that should not be judged by its cover.
The sequels are good too but that first one…just wow.
Pandora’s Star by Peter F. Hamilton is lots of fun. Great read. (The Reality Dysfunction series starts off great then gets inexcusably stupid in later books unfortunately).
Really? I found it quite interminably boring. I am going on to the second in the series, but with serious reservations. If it can’t get and keep my attention very quickly, back to the library it goes. I found the writing dull and the ideas fairly pedestrian, to be honest. The characters were also somewhat wooden. All this, of course, IMHO.
Steven Baxter
Alistair Reynolds
Both pretty much peg my “hard-sci-fi-o-meter”
Outstanding!
I love Peter Hamilton’s books and have read most of his stuff, but I’d think he’s exactly the stuff the OP said he didn’t want when he said that “long pages just to describe the science or technology of the world(s) could leave me cold”. Hamilton’s got a technology fetish. Same reason I was surprised to see the Honor Harrington books recommended.
I hadnt read the OP thoroughly but he asked for a good hard science novel. Then later asks for a book without boring pages long science exposes. Total contradiction in terms.
He might be better off with Frank Herbert’s Dune or anything by Jack Vance. No science rants but solid background.
No, it’s not a contradiction. See my post earlier in the thread.
Example: Heinlein did pages and pages and PAGES of calculations one time, when the best tech available was a slide rule, in order to get the math right for a particular scene in one book. He didn’t show his work to the reader, he just made sure that the math was right, because he was mostly a hard SF writer. Writing hard SF means getting the science and math RIGHT, as best we know, and the writers are allowed some reasonable extrapolation of science and technology. Hard SF doesn’t mean long boring science exposition.
I just finished the last Dresden book myself a few weeks ago. I had devoured the entire series in a span of two months or so. I was dealing with my withdrawal, when I found his short story anthology Side Jobs. Worth picking up if you missed it.
For sci fi, I also recently read
the Engines of God by Jack McDevitt
which I enjoyed.
I came here to recommend Ian Banks’ Culture novels (as noted, Consider Phlebas is a good start but “Use of Weapons” is one of the greatest SF novels ever written – absolutely engrossing. I also wanted to recommend C. J. Cherryh’s “Downbelow Station” – it’s hard SF and it is an absoutely BADASS thriller/adventure story. One of those stories that just hooks you and hurls you through it with your hair on fire going “YEEEEEEEHAWWWWWW!!!”
These are what I came to recommend, as something new and not yet classic. Could not recommend more highly.
Let me also second the Uplift books by David Brin, particularly Startide Rising. (I Kiln People too, but it seems harder to find than the Uplift books).
And if you want to go classic, I think Clark is one of the better writers of characters of the old school bunch. Childhood’s End has well drawn characters and an interesting plot. You will get lots of Heinlein recommendations, so I won’t mention him.
Dragon’s Egg by Robert L. Forward. This is my all-time favorite hard science fiction novel. Forward was an American physicist with a Ph.D. in physics.
Ben Bova’s Grand Tour series is pretty hard near-future SF, all set in the Solar System with no FTL or reactionless drives or anything. The most soft-SF things visible are nanotech and (the remains of prehistoric) Martians.
See also Allen Steele – lots of pretty realistic stories about the daily lives of near-future astronauts.
I would recommend The Book of the SubGenius, but it’s actually too realistic to qualify as SF or, for that matter, fiction.