When friends find out how much Science Fiction I read, they often ask for recommendations. Here's a short list of some semi-recent, but ongoing and generally reliable favorites. The list doesn't touch more golden age writers, like Ray Bradbury, Harlan Ellison, Philip K. Dick, Robert Heinlein, Kurt Vonnegut, Larry Niven, Frederick Pohl, etc. I imagine everyone has heard all those names. I haven't updated the list in ages so it also leaves out more recent faves like James S.A. Corey (read all the Expanse books now, then revel in the TV series -- best SF TV series ever), Ann Leckie (read all her stuff NOW, even her fantasy!), Martha Wells (read every Murderbot story NOW), Adrian Tchaikovsky, Peter Watts, Derek Künsken, Charles Stross, Neal Asher, and more, plus writers that I love but which I'm not sure everyone would, like Greg Egan, and non-SF but brilliant writers like Christopher Brookmyre. This list is old but made up exclusively of moderately contemporary SF writers that I can't imagine anyone failing to appreciate.
I'd hate to even try to pick an order of preference, but you can't go wrong with any of the first eight authors. Lethem and Rucker are the (wonderfully) weirdest. Lethem and Simmons the most literary. Banks possibly the best writer. Card the most philosophical. Hamilton might be the easiest and most fun to read while being the grandest space opera (who else can juggle a dozen worlds and 50 or more characters, and have each of them be unique and believable?). Weber is kind of a guilty pleasure (I'm not normally into military SF). All outstanding.
Where the books are part of a series, I was careful to put them in the correct order.
P.S. As noted, this list isn't at all up to date. There have been more Honor Harrington novels. More Card/Shadow (Bean) novels. Peter F. Hamilton has started another series or two, which are great (as are his earlier Greg Mandel books, that combine SF and detective fiction). Dan Simmons has some new ones... Maybe someday I'll get time to update this.
P.P.S. They're not science fiction, and I normally can't make myself read fantasy, but I have to say, Tim Pratt's Marla Mason urban fantasy novels are fantastic. Smart, funny, totally engaging. He has ended the series but just go read them in order, you'll thank me. I've read every word and only wish he'd change his mind and write more.
His Hyperion/Endymion series, especially the first book...
The Fall of Hyperion
The Rise of Endymion
Orson Scott Card
The Ender Wiggins series
Speaker for the Dead
Children of the Mind
Peter F. Hamilton
The "Night's Dawn" series
The Reality Dysfunction: Emergence
The Reality Dysfunction: Expansion
The Neutronium Alchemist: Consolidation
The Neutronium Alchemist: Conflict
The Naked God: Flight
The Naked God: Faith
plus the prequel, A Second Chance at Eden
(you may still find The Naked God as a single hardback volume,
but in paperback I think it's always two volumes)
Iain M. Banks
I wouldn't want to have to pick a single favorite SF author, but if I were forced...
Everything in his "Culture" universe... (Note: These are in my personal recommended reading order, which is the publication order, except the very first novel, Consider Phlebas, and the third to last novel, Matter, because I don't think he'd quite found his voice yet in Consider Phlebas and I think personal issues were overwhelming him when he was writing Matter. If you read the rest, you'll be glad to have two last novels in the series to read, even if they're, IMO, the weakest. There's also a collection of short stories, The State of the Art, published after Use of Weapons, that contains two or three Culture stories.)
Player of Games
Use of Weapons
Look to Windward (one of my favorite books, period)
The Hydrogen Sonata
Plus these standalone novels:
The Wasp Factory
The "Galactic Center" series, especially the first two or three
In the Ocean of Night
Across the Sea of Suns
Great Sky River
Tides of Light
Sailing Bright Eternity
(I'm less enamored of Benford's later work, because he decided to focus on only slight extrapolations of contemporary science; still well written, just not my cup of tea.)
A Fire upon the Deep (Zones of Thought 1)
A Deepness in the Sky (Zones of Thought 2)
Since I originally wrote this there have been quite a few "Great Ship" novels and short stories, all of which are worth reading, and most are amazing. Truly, the "Great Ship" stories are some of my favorite works of science fiction, ever.
Marrow (first in the "Great Ship" series; you have to ignore the enormous number of typos, for a great story, unless they've revised it)
Gun, with Occasional Music
As She Climbed Across the Table
Girl in Landscape
The Wall of the Sky, the Wall of the Eye
(And pretty much anything he writes, with my favorites being Amnesia Moon,
As She Climbed Across the Table, and Motherless Brooklyn; the only exception at time of writing
is his most recent, Fortress of Solitude, which neither Levi or I could finish).
Forever Peace (title approximate; sequel to Forever War)
Forge of God
Anvil of Stars (sequel to Forge of God)
(Like Benford, Bear has constricted his vision for some of his more recent writings.)
Frek and the Elixir
All of the Honor Harrington military-in-space novels,
of which there are many; these are a bit of a guilty pleasure,
but they are fun and engaging; the extra, unnumbered books
are related and the stories by David Weber are uniformly good, but
there are some other authors whose stories aren't as good; in
Shadow of Saganami Honor Harrington is not a central character;
I believe there are lots more now, but I stopped reading these.
1. On Basilisk Station (Honor Harrington Series, Book 1)
2. The Honor of the Queen (Honor Harrington Series, Book 2)
3. The Short Victorious War (Honor Harrington Series, Book 3)
4. Field of Dishonor (Honor Harrington Series, Book 4)
5. Flag in Exile (Honor Harrington Series, Book 5)
6. Honor Among Enemies (Honor Harrington Series, Book 6)
7. In Enemy Hands (Honor Harrington Series, Book 7)
More Than Honor (Honor short stories; multiple authors)
8. Echoes of Honor (Honor Harrington Series, Book 8)
Worlds Of Honor (Honor short stories; multiple authors)
9. Ashes of Victory (Honor Harrington Series, Book 9)
Changer of Worlds: Worlds of Honor 3 (multiple authors)
10. War of Honor (Honor Harrington Series, Book 10)
The Service of the Sword: Worlds of Honor 4 (multiple authors)
11. Crown Of Slaves (with Eric Flint, Honor Harrington Series, Book 11)
The Shadow of Saganami (start of new series featuring Honor's students)