Frank Herbert but as others have recommended Dune I will point to his sci fi short stories - often as dark as Dune but with brevity!

Ursula Le Guin is perhaps my favourite sci fi author, her books set in the Hainish universe are awesome with The Dispossed as one of her most famous. If you like fantasy too you should check out her Earthsea series.

Iain M Banks if you like space opera - his Culture novels are vast in scope and always entertaining.

...Science Fiction, dude. As in, scienticif and stuff. Not Objectivist Fiction As much as I like Goodkind, he doesn't belong here...

there are alot of Warhammer 40.000 (40k) books, personally loved Firewarrior   but maybe it's becuase i play T'au...

never read, but heard that DUNE is a really good one either (even a film was made out of it)

I have to say, I'm glad to see at least one other Drake fan, his work certainly isn't for everyone. The RCN series is rather tame by his standards, but extremely good. Part of the fun in reading his books is figuring out what era of history he's taking ideas from - most of his work is based on real history or literary works. The RCN series is based on the tech and politics of the Age of Exploration. Northworld is based on Norse mythology. Several stories in the Slammers universe are based on Homer.

I saw The Shiva Option up here, but not the rest of the series it's in. That's a shame, In Death Ground (the one immediately preceding TSO) is IMO a better book. Insurrection (set after TSO) is also good, but suffers a few inconsistencies due to being written first.

I saw passing mention of Niven, without mention to his master works. Find some of the Known Space series, just be sure to read them in as close to chronological order as possible. Ask if you need advice as to read order.

The Honorverse (David Weber) does get a bit predictable, or at least the political aspects do. On the other hand, he's still got another 12+ books planned for it, and I can't see how the war with Haven can take more than one or two more. After that, I expect focus to shift more to the Solarian League and various (currently) secondary characters.

I have more, but they'll have to wait until I get home to look through my book shelves.

David Weber's Honorverse is perhaps the best series I've ever read. David Weber has written dozens of books, each one better then the last. The first book of the series is On Basilisk Station, and the last is At All Costs.

I can't even begin to tell how horrible it would be to miss Tad Williams - Otherland series.. I want to read it for the first time again... It's awesome.

Hey, a book recommendation thread! I love these things!

Alastair Reynolds' Revelation Space series, as mentioned, is really good. Epic space opera, ultra-realistic, lots of mind-expanding new ideas. However, bear in mind that his universe is a very dark and scary place. Enjoy in moderation, take frequent breaks, do not operate heavy machinery while reading, etc. Also check out his short story collection Zima Blue if you'd like something (relatively) lighter.

Isaac Asimov is, of course, awesome no matter what you read. I especially recommend the Foundation series which chronicles the fall and rise of galactic civilization over thousands of years. Nightfall is also interesting; it explores the ramifications of evolving on a planet with no day/night cycle.

Peter Hamiltion's Pandora's Star and Judas Unchained were also very good. Pandora starts off incredibly slow with most of the book being spectacle fiction, but that's because it's not a standalone story. Judas is the other half, and the action completely justifies the 300+ pages of build-up. (Plus, Pandora ends with a total wtfpwnt moment for everyone. So worth it.)

Now that those are out of the way...

I'm surprised no one's mentioned Vernor Vinge, as A Fire Upon The Deep would be of particular interest here. It's about a small crew of humans and plantlike aliens racing to find the key to destroying a malevolent godlike entity, while half the species of known space incite interstellar wars and the other half provide color commentary over the galactic equivalent of usenet. A Deepness in the Sky is also really good. It's a loosely related story in the same universe, but deals with a nomadic merchant fleet that travels at sublight speeds.

For something different, he also wrote Rainbows End. It's a near-future story about a man who is suddenly cured of severe Alzheimer's after having it for 20 years. He was just beginning to understand this "intarweb" thing when he got sick, and now he's in a world where everyone has wearable computers with gesture-based interfaces, the kids are enrolled in affiliate programs, and all media is based on augmented reality. The culture shock is bad enough, but then he gets tied up in an international conspiracy involving bioterrorists, his family, and a talking rabbit.

But the one book you definitely must read is Singularity Sky by Charles Stross. It's just one big futuristic WTF moment from start to finish. Imagine a colony of 19th-century Russians suddenly gaining access to Star Trek-style replicators. Now imagine that the bizarre ramifications of this cause their leaders to try stopping it with time travel, in direct violation of a law put in place by a sentient AI, and the minimum sentence is Death By Supernova. Still, it's better than what the mimes are planning...

I have read a lot of star wars hence my account name, eventualy they got boring stoped reading and never found a good one recently. The ones that I like is Outbound Flight, the Vong set, Black Fleet Crisis, and the Dark Nest Trilogy

My favorites are the Lensman and Skylark series by E.E. "Doc" Smith, Ph.D., Sector General novels by James White (Sector 12 General Hospital), Pern novels by Anne and Todd McCaffrey, the Talent books by Anne McCaffrey, Darkover series by Marion Zimmer Bradley, too many books by Andre (Alice Mary) Norton - Grand Dame of science fiction, now deceased. There are the Paratime novels, of which I forgot the author's name.

There is James P. Hogan who wrote the Giants series (currently 5 books): Inherit the Stars, Gentle Giants of Ganymede, Giants' Star, Entoverse, and Mission to Minerva. He aslo wrote a bunch of other books, of which I will begin getting.

If you want happy SciFi, read anything Star Trek. The federation is sickening good.

Isaac Asimov's Robot and Foundation series.  Now *that's* some epic science fiction! 

I'll also strongly second Weber's Honor Harrington novels.  Although I can't compare it to the Horatio Hornblower books (I've not read them yet), it's definitely a great space opera series. 

Gah!  No. 

With apologies to you and his other fans, I just don't understand why people find that trilogy to be so bloody brilliant.  The first 150 pages of Red Mars was about all I could stomach before wanting to slit my own throat.

Although I like science fiction, I'm not too keen on 'space operas' they always seem to be written rather clumbsely.

As such I would heartly recommend more "Terristiral bound Science fiction".

Brave New World and Nineteen Eighty Four, written by Audlex Huxley (sp?) and George Orwell respectively. I personally feel that Nineteen Eighty Four is the supperiour book but both are fantatstic.

Robert Matherson's I am Legend is also a cracking read, even though its knowledge of Microbiology is VERY out of date, even for when it was written.

The Day of the Triffids by John Wyndham is also a very good survival Sci Fi novel if your intrested.

Flowers For Algernon (by Daniel Keyes) is another classic book. Very well written, and very moving. Won't say too much about it incase i ruin the plot.

If your looking for something with a VERY BLACK sense of humour I you can't go far wrong with 'Slaughterhouse V' by Kurt Vonvet (sp?)

If he wants a science fiction novel why are you recommending Horatio Hornblower. He was the main character in C.S.Forestor (sp?) series about the Naval warfare in the Napolonic wars. And although the books are VERY GOOD, there hardly science fiction. As Napolion did exist, I know its hard to beleive that a French man nearly took over the world but it is true. And we British did stop him (European Histroy, suppose thats sort of ignored in America /jk)

Simply as i found it a really good read i'll add:

Agent of Vega by James H. Schmitz, 1960

otherwise i'm a huge fan Iain M Banks, particularly Feersum Enjin if you want a snap shot of his work rather than getting into the culture universe (you'll never escape if you do =P)