I thought terminator was based on a nightmare James Cameron had.  Or is that just hogwash he tells people to make it sound more interesting?  Ted Geisel used to do the same thing. 

Tim, I agree with many if not most of your picks. I guess guys like Simmons, Card, and Sawyer just haven't been around long enough to be considered, but I do whish you had included at least one of the contemporary heavy-hitters if for no other reason then sci-fi has changed so much just in the last decade.

I'd move Herbert up to at least the sixth spot given his influence on the genre just with his Dune books alone, but I see that being prolific was a necessary part of your criteria.  

I dig the pictures and many of the guys are heroes of mine, but it does look like they're all at a bit of a Viagra convention.

Tough to argue with these. Though not usually thrown into the sci-fi category in the traditional sense, I would add Michael Crichton to this list. Terminal Man, Andromeda Strain, Jurrassic Park, Congo, Sphere...these are classics.

what about HG Wells?  Its long held that his vision, although considered fantasy at the time, is now everyday science.  Even his calculations for launching a spaceship to the moon are near what it takes to launch ships into space.  where's the love?

Krakken...*I did mention Wells and Jules Verne goes, but as most people agree, the Sci-Fi era began with the publication of Amazing Stories in 1926 and thus my list really starts there and moves forward

I have to agree Herbert should be moved up Dune has had massive influence, it could be considered the Sci-Fi bible, Paul Atreides is certainly its christ. I would argue nothing as to Clarke's place as wise as he was inteligent the Budah, of Sci-Fi.

I do think the present was difinitely overlooked, you dont think William Gibson, "the father of cyberpunk" should have been on the list????!!! Because of his body of work?? Although many genious are measured in the body of their work, that should by no means be a reason to exclude someone!! Youve heard of quality not quantity? You are kidding right?

Not mentioned, Edgar Rice Burroughs was a Sci-Fi writer, no question

Verne and Wells are in a class all their own. The people on this list who are all greats, simply followed in the wake of "The Fathers Of Science Fiction".

Vlomski...I hear what you are saying.  Problem is that ALL the writers on the list have enormous quality AND quantity.

I look at Gibson like a pitcher in baseball who throws a perfect game.  They get in the Hall of Fame for that achievement, but not necessarily for their careers.  Neuromancer was definitely a perfect game for Gibson but time will tell if he has the numbers to make it to the hall.  Hope that makes sense.

Good to see Gordon R. Dickson getting that honorable mention. You don't see his name etting batted around much, anfdd I get the impresion a lot of people haven't heard of him, but his Child Cycle series among oother thing have been brilliant. 

Good list.  I was thinking, where's Card, but glad he was mentioned at least.

I guess it's a matter of taste, but I enjoy Asimov more than Clarke.