I've attached an arbitrary (and by no means exhaustive) list  of SF authors - some old, some new. Some well-known, others not so well-known. You get the picture.

Your challenge is to rank your top ten favroite SF authors from this list. I know so moe of your actual favorites may not be on the list. If you want, do a P.S. with them after the top ten from this list. After everyone has had a chance to vote, I'll tabulate the results, and show the results. You may want to look at Amazon or Wikipedia for a particular author to refresh your memore on what they wrote.

For those of you that are new to science fiction or unfamiliar with one or more of these authors, your additional challenge is to read a book by each one.

Here goes (it's a long list):

Frederick Pohl, C.J. Cherryh, Stephen Baxter, Isaac Asimov, Robert HeinleinKeithLaumer,

S.M. Stirling, Eric Flint, David Brin, David Weber, Charles Stross, Greg Bear, Joe Haldeman, Wil McCarthy, William Gibson, Jack McDevitt, Cordwainer Smith, H. Beam Piper, Phillip K. Dick, Michael Marshall Smith, Larry Niven, Robert Silverberg, Peter Hamilton, Tobias Buckell, Connie Willis, Walter Miller, John Brunner, Jack Womack, David Drake, Neal Stephenson, Robert Charles Wilson, George Alec Effinger, John Varley, Poul Anderson, Arthur Clarke, Andre Norton, Vernon Vinge, Jerry Pournelle, Michael Williamson, James Blish, Cory Doctorow, Anne McCaffrey, Geoff Ryman, Neil Gaiman, Gene Wolfe, Ted Chiang.

Good Luck!

OK, this might be a little arbitrary, but tossing out those I have never read, and those I don't like, I came up with these 10:

#1 - Robert Heinlein - Probably my favorite author overall.  I grew up reading his YA novels, and have read 37 of his books total.  A great writer and a great storyteller, in my opinion.
#2 - Joe Haldeman - I started reading his books when I was in high school and have kept up with every new release since 2000.  I consider him the best modern hard SF writer.
#3 - William Gibson - I love cyberpunk, and I think Neuromancer is one of my top few favorite novels.
#4 - Philip K. Dick - I like weird and different types of writing, and his books definitely fit the bill!
#5 - Poul Anderson - I read 14 of his books in a two month span.  I think he has good stories, if not completely earthshattering.  I especially liked the Flandry stories.
#6 - James Blish - Another different kind of author.  I've only read a few of his books, but was impressed.
#7 - John Varley - Just had to add him because the short story "Press Enter" is one of my all-time favorites.
#8 - Larry Niven - The Mote in God's Eye with Jerry Pournelle is my favorite of his books, and I like the different and complex worlds he creates.
#9 - Isaac Asimov - I don't care for some of his more famous works (such as the Foundation series) but I do think he was a pioneer, and I like quite a few of his other novels.
#10 - Greg Bear - I have a hard time getting into some of his books, but others I loved.

Authors not on the list that would definitely be in my top 10 are Alfred Bester and Frank Herbert.  Orson Scott Card is a crossover, author, but would probably be up there for the Ender series and my favorite of his short stories, "Dogwalker."  I also think Tanya Huff might make it in my top 10 with the Confederation series, though she writes more paranormal/fantasy stuff. 

I can't play. I like less than 7 on the list. Too many on the list that I simply don't like. Period. And I consider Gaiman a fantasy writer.

Too many Golden Oldie Moldies (sorry Matt <g>) are considered "classic' just because they were writing in the field when it was new and exciting.

Where's John Scalzi? Lois McMaster Bujold? Allen Steele? Charles Sheffield?  Nancy Kress? Elizabeth Moon?

I should have included Scalzi,  Bester, Card, and Herbert. I appreciate the other suggestions. Those will be authors I sample this year. Always looking for new ones.

Sorry Karen, but I disagree.  If you just plain don't like dated fiction, that's one thing, but the authors I mentioned are ones I believe are truly good writers.  I was an English major in college and I'm picky about technical skill of writers.  The fact that I still read and enjoy Heinlein is becuause of his writing, not the fact that he's a 'classic' in the genre.  SF has a pulp histry from the early 1900's and even before.  It was not new even in the late '30s when Heinlein started, and was old hat by the '50s.

Ah. I go for story and characters ... not technical skill. I basically went thru Bob's list saying "Ick!" "And ick!" "Boring!" But I *do* like RAH, never fear ...

But what would book stores be like if we all liked the same thing? :-)

My top 10:

1. Vernor Vinge - Awesome story-telling and exciting plots. Interesting and enjoyable characters. And of course he is terrifically imaginative.

2. Isaac Asimov - All his series are great. He's perhaps not the best at writing, but his plots are generally excellent.

3. Connie Willis - I enjoy both the humor and sadness in her novels. They are usually very well written, as well.

4. Lois McMaster Bujold - She also has terrific characters and exciting plots. My only issue is that her books are not so unique. She does write the cliched plots quite well, though.

5. Philip K. Dick - I've read almost all his novels, and most of them are great explorations of psychology and strangeness. I didn't really enjoy his pseudo-religious/philosophical books, though (see: VALIS).

6. Dan Simmons - The Hyperiod Cantos is one of the best space opera series of all time. I haven't read any of his other books, but that's enough to make it.

7. Robert A. Heinlein - He has some amazing books (The Moon is a Harsh Mistress, Starship Troopers, Double Star, Farmer in the Sky) and some truly terrible ones (I Will Fear No Evil comes to mind). The obvious sexism and boring lectures in his books annoy me (particularly in the later rnovels).

8. Larry Niven - Ringworld is great, both for the story, characters, and of course the world building. Like Heinlein, he has some terrible books though.

9. William Gibson - The Sprawl trilogy is superb (I ejoyed Mona Lisa Overdrive the most for some weird reason). His other books aren't as great (Pattern Recognition was alright).

10. Arthur C. Clarke - Has only a few major books (Rama, 2001, Fountains of Paradise), but they are excellent and very influential.

Now that I think about it, I should probably have included Ursula K. Le Guin instead of someone. Oh well, too late.

Well, I only like five. I like them a lot but. . .

1. Connie Willis

2. C.J. Cherryh (a love/hate relationship; there a couple of hers I couldn't finish (rare with me) and several that are on my best ever list)

3. Isaac Asimov

4. Arthur C. Clarke

5. Anne McCaffrey (I loved her as a teen, but as an adult I find her writing pretty poor.)

I would point out that that is a VERY male dominated list; for classic authors I'm surprised you didn't include Ursula LeGuin and Marion Zimmer Bradley, and for current writers that have an impressive backlog and a lot of awards, Lois McMaster Bujold really needs to be on there. And just to avoid sounding like a complete feminist, I'm also saddened you missed Gordon R. Dickson and Orson Scott Card. My complete top ten would be the following:

1. Lois McMaster Bujold

2. Marion Zimmer Bradley

3. Connie Willis

4. Sheri S. Tepper

5. Orson Scott Card (though I refuse to read most of his newest stuff)

6. C.J. Cherryh (with the caveat above)

7. Isaac Asimov

8. Elizabeth Bear

9. Gordon R. Dickson

10. Anne McCaffrey (with the caveat above)

I would have liked to put Arthur C. Clarke up there instead of Anne McCaffrey, but I've read fewer of his books and Anne McCaffrey was a real love of mine when I was younger.