Ok so whos the best Sci Fi Writer???

[PrinceOfNaturism]

I am a big fan of PJ Haarsma.

[Womberling Wurzel]

Michael Moorcock
William Gibson
Daniel Keyes
Philip K Dick
HG Wells
Douglas Adams
Sheri S Tepper

To name a few

[Alan-J]

For ones already mentioned I wil agree with:

Douglas Adams
Larry Niven
Philip K Dick
Robert Heinliein
Frank Herbert

And to add some I dont think mentioned yet:

Anne Mcaffrey (yes she does scifi too)
Philip Jose Farmer (you have to try "To your scattered bodies go" even though at this stage the series isnt full sci-fi)

Many others mentioned I know are good from their reputation and what they have inspired, but as I havent directly read them I wont add them to my list.
:)

[Dj1979]

David feintuch for seafort saga. (First book midshipmans hope) 7 books, I read them all every 2 years or so they are that good.   
Orson Scott card was a magician with the ender series, but he is rather homophobic so that ruined him for me...!

I love sci fi and there are many others I could mention as stand outs, but the seafort saga is such a fave of mine he wins.

[ToneBender]

I can't believe I haven't replied to this one yet.

Hmmmmm....

Isaac Asimov and Mary Shelley for two.

[Gman707]

Has anyone mentioned Brian Aldis and Robert Heinline yet? Both excellent writers.

[Stephen]

Just throwing this out there, Steven Moffat, he creates this crazy work with emotions and drama, and overall mix of everything packed into sci-fi at the same time, and it is always perfect. Yes, I am referring to his work on Doctor Who.

[Gman707]

I love dr who but i dont like moffat much. He often tries too hard to be deceptive in his story tellingand ends up nonsensical.  He made a mess of series 6 of dr who and series three of sherlock. Luckily he seemed to be less up his own bottom on series 7 and mostly avoided his usual massive plot holes.

[softynude]

My fav is Arthur C. Clarke

[VandyFan08]

While I don't think most of his writing fits cleanly into "sci-fi," I've recently gotten into Steven King.  Most people know of him for his horror books.  But, some of my favorite reads recently are his "Under the Dome" (which has been made into a TV series which I need to watch) and his self-proclaimed Magnum Opus, "The Dark Tower."  For those of you who want to lose 2-3 months of your life delving into an incredible story spread over 8 books and around 8000 pages, it is an incredible journey that can be summed up by the first line of the series (which has been suggested as one of the best first lines to a book ever in certain lists):

"The man in Black fled across the Desert, and the Gunslinger followed."

[nudesailor]

William Gibson
China Mieville
Christopher Priest
Jack Womack

[tkh]

Daniel Eschbach, because his stories seem to could be real

[Surin Blastanos]

Andy Weir is fantastic, as is James S.A Corey

[the_nude_topher]

Disclaimer: I am not a Sci Fi fan. But I did enjoy some of Christopher Rice's books.

[Gusse]

Just read the whole Foundation series and couple more Asimov's books.
Isaac Asimov. Even after 80 years, Foundation books are interesting and suprisingly accurate.