... an all-time best science fiction / fantasy contest. Let me guess: the most popular book will win - the one that has sold the most copies. So that would be... The Lord of the Rings? Jennings Goes to Wizard School?
And look at the match-ups: Ghormenghast versus Dune? The Gunslinger versus Hyperion? The Shadow of the Torturer versus The Colour of Magic?
It's bad enough the sf / fantasy community handing out awards in popularity contests*. Choosing a "best" book is such a subjective process, anyway - and that's assuming a representative sample actually bothers to vote. On a shortlist which is itself unanimously agreed to contain the "best" works of the year...
(* judging by this year's Nebula Award shortlists, it seems you can't trust jury awards either...)