Asklemmy

Neil Gaiman

He died in 1982 but his works are hugely influential:
Philip K Dick.

Sir Terry Pratchett.

A phenomenal author whose ability to weave a story is fantastic, but was also adept at writing in jokes and references that make re-reading the novels a delight.

Brandon Sanderson

The man is a top flight book generating machine. Where he's taking the Cosmere, I don't know, but I'm gladly awaiting for the novels he'll write the in future to find out. Reading the Stormlight Archive and Mistborn is a joy.

I also really enjoyed how he wrapped up The Wheel of Time. He is much less reluctant to kill off characters than many other authors, and that series needed some serious character culling to bring closure.

Umberto Eco.

Two authors I haven't surprisingly seen mentioned

Neil Gaiman is great. If you haven't read his works yet, start with *the ocean at the end of the lane". A wonderful, short read.

This second one is going to be controversial.

George RR Martin. The books are actually well written, and yes the final book probably won't get written, but it won't take away from your enjoyment. He is a very good writer.

Cory Doctorow and I suggest reading Walkaway. I found it transformative.

Terry Pratchett (first book 1971 so barely counts haha)

Neil Gaiman. The man can write novels, YA novels, graphic novels, children’s books. And they all have such well crafted worlds that you just want to lose yourself in them.

I also think Neal Stephenson and Corey Doctorow deserve WAY more attention than they get.

This isn't a perfect example but Cormac McCarthy has been my favourite author for years now, and his first major work Suttree was from '79.

My all time favourites novel is Blood Meridian from 1985. If you're familiar with metamodernism, which is basically very modern works that have their cake and eat it when it comes to modernist ideals and postmodern critique, you'd clock that practically every western is either a modernist white hat western or a metamodern "the west is grim and hard, but also fucking cool" western. The only straight postmodern takes on the west that I know of are either Blood Meridian or pieces of work that take direct notes from it, such as the films Dead Man from '95 (except maybe the Oregon Trail video game from. 85'). Blood Meridian otherwise is a fantastic novel which meditates on madness and cruelty, religion and fate, race, war and conquest and so many other themes. It also has one of the best antagonists ever written in Judge Holden, a character who I would have called a direct insert of Satan if not for the fact that his deeds and the novel as a whole are closely inspired by true events. I feel the novel takes inspiration from Apocalypse Now, specifically the '79 film and not Conrad's 1899 novel Heart of Darkness. If you enjoy that film, you're likely to enjoy this book. The opening and closing chapters are fantastic, but I often find myself re-reading chapter 14. It has some of the best prose and monologues of the entire novel, and encompasses in my opinion the main turning point of the novel.

His other legendary work is The Road, a 2006 post-apocalyptic novel. I'll talk on this one less but as our climate crisis grows and our cultural zeitgeist swings more towards this being the critical issue of our time, the novel fantastically paints itself as both a fantastic warning to our 21st century apocalypse and the unresolved 20th century shadow of nuclear winter. Despite this, it hones in on a meditation of parenthood and could be considered solely about that, with other themes of death, trauma, survival and mortality being explored through parenthood. Of course the unsalvageable deatg of the world that make the setting also makes this theme extra tragic. There is an adaptation into a film from 2008 but it isn't anywhere near as potent as the novel and I'd suggest should only be seen in tandem with reading the novel. The prize of this novel has really evolved to fit the novel too. McCarthy is renowned for his punctuation lacking prose, but where Blood Meridian is practically biblical in its dramatic and beautiful prose which juxtaposes the plain and brutal violence, The Road sacrifices no beauty in it's language but is so somber and meanders from mostly terse to so florid, while also always perfectly feels like how the protagonists are seeing their world.

Cormac McCarthy, wrote some books you might have seen as movies such as The Road and No Country for Old Men.

Blood Meridian or The Evening Redness in the West is a crazy good book.

Terry Pratchett! The Discworld books have kept me busy for years now and I don't even consider myself much of a reader.

Can I cheat? Ursula K LeGuin's first famous book, A Wizard of Earth sea, was published in 1968. Amazing stuff. Also I love her short story, The Ones Who Walk Away from Omelas.

Iain M. Banks.

Alan Moore

Saga of the Swamp Thing and Watchmen are two amazing runs of comics he wrote.

Huge fan of his recent-ish novel, Jerusalem.

• Greg Egan
• Rudy Rucker
• Vernor Vinge

Hard, computational SF aren't given nearly the respect they should, and these apply math, comp sci, and physics in a way nobody else does. If there's any civilization in the future, they'll be seen as visionary.

Runners-up are Robert L. Forward, Alastair Reynolds, but Forward has very little computation, and Reynolds doesn't show his math too often.

I hesitate to call her a great author in her own right and I detest her attitude towards transwomen. That said, J.K. Rowling's Harry Potter series transformed the young adult fiction genre from a bit of a wasteland of Nancy Drew and Hardy Boy novels into a quality genre with significant cross-generational appeal.

I'll mention Orson Scott Card as well, but his books have worn thin over time as he squeezes every penny out of the Enderverse. Ender's Game got me through a miserable hospital stay as a young child, so it will always have a special place in my heart. Speaker for the Dead I also loved.

Andy Weir -from a not too avid reader

Stephen King is definitely a great author

James S A Corey

It's a pen name but still.

• John Scalzi - Old Man's War series and The Interdependency series
• Dennis E. Taylor - Bobiverse

So many good answers already that I agree with. So I'll add James Ellroy and Clive Barker

For Ellroy, the entire LA Quartet remains a pivotal sea change in "hard boiled" crime fiction; taking a lot of the conventions created by the likes of Hammett and Chandler and updating them for a modern audience.

Barker is a more personal choice. But his writing is just so evocative and descriptive that I couldn't NOT mention him. Imajica literally changed my literary life, with Weaveworld being (in my opinion) a less dense, more reader friendly version of Imajica.

Philip Pullman of his dark materials fame?

Gabriel Garcia Marquez started before 1970 but his career stretched long after.

A few years off from your criteria, but Ursula K. Le Guin released A Wizard of Earthsea in 1968. However, she had been pretty prominent in science fiction for the decade.

Important enough to inspire Pratchett and Miyazaki (of Studio Ghibli).

She's a hugely influential writer.

I just thought of another: Bernard Cornwell. His novel series (Sharpe, The Last Kingdom, etc) are phenomenal historical fiction.

Gene Wolfe - the style of his sci-fi is mesmerizingly mysterious, even the mundane things described take on sinister tones

Tom Robbins and Tim O'Brien

Roberto Bolaño

N. K. Jemison

Daniel Suarez "Daemon" series was fantastic!

Sarah Waters

off-beat:

• Vikram Seth (polyglot) – A Suitable Boy
• Ryszard Kapuściński (journalist)

aside from some of the more obvious choices (rushdie, wallace, mccarthy, morrison):

don delillo, esp. underworld and white noise

ted chiang, esp. exhalation

marilyn robinson, esp. housekeeping

denis johnson, esp. jesus' son and tree of smoke

colson whitehead, esp. the intuitionist and the nickel boys

and while relatively new so maybe not at the same status as some other writers, jamil jan kochai and nana kwame adjei-brenyah will be making lists like these in the future if they keep writing the way they have.

To me, it has to be Steven Erikson. Malazan series is simply amazing.

Lots of great sf/fantasy authors mentioned already, including some I'd argue for as great writers regardless of genre (Ursula K. Le Guin, Gene Wolfe, N. K. Jemisin).

I have three more to suggest in this genre and from this period:

• C. J. Cherryh (Cyteen, Foreigner series, lots more) uses the lens of alien societies -- just different enough from ours -- to make us look critically at the structure of our own;

• Sheri S. Tepper (Grass, Raising the Stones, The Gate to Women's Country) carries one or another of the dark currents underlying our culture to its horrifying conclusion, and shows us what we get;

• Lois McMaster Bujold (Vorkosigan saga) gives us a hilarious and improbable hero who utterly transcends his disabilities, in the end perfectly embodying what it seems he could never hope to be.