What is your purpose in reading SF?

Do you want to be better able to understand the sort of references someone on Less Wrong might make?

Then I'd suggest The Moon is a Harsh Mistress, A Fire Upon the Deep and Accelerondo.

Do you want to be exposed to a lot of futurism ideas?

Then I'd suggest Permutation City, Blindsight and Rainbows End.

Do you want to read something that's just fun?

Then I'd suggest A Civil Campaign, On Basilisk Station and Ender's Game.

All of these books are written by people who have written multiple books, if you find you like them, you can easily read their other titles.

I agree with many of the recommendations offered already. If you like Greg Egan, you may also like Ted Chiang. For a free taste of Egan, try Crystal Nights. For a free taste of Chiang, try Exhalation.

Since there seems to be quite a bit of overlap here already I'd just like to list three authors who haven't been mentioned yet. Extremely highly recommended.

• Stanislaw Lem: pretty much everything, but you should start with Cyberiad and His Master's Voice.

• Arkady and Boris Strugatsky: First and foremost I recommend Roadside Picnic. (later adapted to the Stalker movie and the Stalker games). Their other books range from decent to great.

• Jorge Louis Borges: everything. He was not strictly a sci-fi author but was actually marketed in the Soviet bloc as sci-fi, and justifiably so. I would call him a writer of "philosophy fiction".

Also don't miss out on Orion's Arm:

Welcome to Orion's Arm, a scenario set thousands of years in the future where civilization spans the stars. Godlike ascended intelligences rule vast interstellar empires, and lesser factions seek to carve out their own dominions through intrigue and conquest. And out beyond the edge of civilized space and the human friendly worlds, adventure awaits those prepared to risk all.

Come join us in this ever-expanding collective worldbuilding effort. Within the vast universe that is Orion's Arm you will find:

• Hard Science
• Plausible Technology
• Realistic Cultural Development
• A vast Setting
• 10,000+ years of historical development Realistic Exobiology

See here. Especially here.

I recommend The Golden Age by John C Wright. It is about the closest thing to a genuine post-singularity utopia I've ever read in Sci Fi.

The main character is a (kind of) rationalist hero, but he lives in a world where some humans have chosen radically different "neuromorphologies". Some people live in Hive Minds, some in dreamy, emotional, intuition-based "covens", etc.

Philip K. Dick was pretty much the third classic SF guy after Clarke and Asimov in SF translated to Finnish, with Heinlein being almost unknown here. Dick's stuff is clever and consistently off-kilter in some way, and often somehow tied to the 60's counterculture. A big theme is identity and reality breaking down in some way. The Man in the High Castle, Ubik, A Scanner Darkly and VALIS are good. The short stories are also full of all sorts of weirdness.

Stanislaw Lem on Dick

There have been extensive discussions of this, but I'll throw in my two cents.

Read because they were recommended on LW: "A Fire Upon the Deep" and "A Deepness in the Sky" by Vernor Vinge

Recent favorites: "Red Mars" by Kim Stanley Robinson

Windup Girl - Paolo Bacigalupi

This is the most enjoyable book I read last year, and I believe it won the 2009 Hugo. After you're done reading you have a few fridge moments ("wait... that probably couldn't work") but while you're reading it it's pure enjoyment and it's really easy to overlook those for the sake of the story. Set in a post oil-crash world, focusing on working class characters trying to make a living while still doing something bigger with their lives. Great action, great plotting, really interesting characters, and a really unique society (from an American point of view anyway).

Click here for a comment thread containing many sci-fi recommendations, from the open thread in January 2010. This includes a long list of recs that I posted in January 2011, having failed to read the date of the thread.

I, Robot by Isaac Asimov
Ender's Game by Orson Scott Card
The Mote in God's Eye by Larry Niven and Jerry Pournelle

Anything by Ian McDonald should be worth a read. I remember liking Hearts, Hands and Voices. A lot of people seem to have liked the more recent River of Gods and Brasyl.

Quite a classic collection here..

Douglas Adams - The Hitchhiker's Guide to the Galaxy

Also try Heinlein's Stranger in a Strange Land and don't miss Sagan's Contact.

I would suggest looking through the Baen free library. Most of the content is high quality, also it's free so you can easily sample the first chapter or two of different books to see what you like. If you like alternate history I would particularly recommend the 1632 books. They are one of my favorite series in terms of entertainment value and also have some interesting rationality realted themes. Specifically they involve a lot of plaining and decision making both of which tend to succeed or fail in realistic ways. For example serval characters fail at their goals because they add unnecessary complications to their plans. http://www.baen.com/library/defaultTitles.htm

Start with early science fiction.

Read We by Yevgeny Zamyatin from 1921

This book influenced some of the greatest writers of the 20th century.

Here is a good blog post about We: http://ieet.org/index.php/IEET/more/dvorsky20110405

Also read Frankenstein, one of the first science fiction books ever published - 1869

It is a free eBook on Google: http://books.google.com/ebooks/reader?id=2Zc3AAAAYAAJ&dq=we&as_brr=4&printsec=frontcover&output=reader

I really liked Bruce Sterling's Schismatrix when I read it in high school. It's set in Sterling's Shaper/Mechanist universe, where humanity is expanding into the solar system and modifying itself with cybernetics and biological engineering, slowly evolving into something posthuman. Sterling's Holy Fire was a bit more down-to-earth later transhuman novel I also liked.

Dan Simmons is a bit hit and miss, but his Hyperion might be a pretty good choice to read if you're going to read exactly one SF novel. It's basically a Canterbury Tales style framing story, with the protagonists' stories being pastiches that span the history of written SF from pulp-era planetary romance to post-cyberpunk. There are three sequels that are ok, but don't measure up to the first book.

Simmons' more recent Ilium/Olympos duology drives a mountain of literary references that threaten to drown any internal coherence in the rest of the story into post-9/11 crazy right-winger bat country. Still pretty entertaining on the account of Simmons really knowing how to write stuff, but more just weird than good weird.

I'm sure these have already come up, but I'll add my voice in enthusiastically recommending the following -

• The Diamond Age by Neal Stephenson
• Accelerando by Charles Stross
• City at the End of Time by Greg Bear
• Neuromancer by William Gibson

Accelerando will have rather familiar themes and ideas to anyone who's spent significant time on LW, in particular, although that goes for the others to a slightly lesser extent. City at the End of Time was probably the most "work" for me to read out of the four - I enjoyed it greatly, but it's a book best savored slowly. Neuromancer is pretty much the grand icon of cyberpunk, and Gibson's facility with densely evocative language makes me jealous. The Diamond Age is probably the one I had the most lighthearted fun in reading, the easiest to follow, even though it's a very thought-provoking story.