I have immense respect for Herbert, Zelazny, Disch, Spinrad, Ballard, Aldiss, Simak, Budrys, Silverberg, Leiber, Bester, Farmer, Sturgeon, Heinlein, Bradbury, Clarke, Dick and Lem, but my all-time favorite is Harlan Ellison, who did not write novels, but who has won more Hugos and Nebulas  for his passionate, erudite and meticulously crafted short stories than any other speculative fiction writer in the history of the genre.  DEATHBIRD STORIES, his monumental collection of connected short stories concerning contemporary godfoms, is a modern classic.  To quote from its introduction:

Harlan Ellison * Deathbird Stories *
(Book Quote)
Introduction: Oblations at Alien Altars / xiv

~ " Gods can do anything. They fear nothing: they are gods. But there is one rule, one Seal of Solomon that can confound a god, and to which all gods pay service, to the letter:
When belief in a god dies, the god dies.
When the last acolyte renounces his faith and turns to another deity, the god ceases to be.
They know the terrible simplicity of that truth, the mightiest and the mingiest of gods. They have seen their fellow gods go down to obscurity and banishment for lack of believers. They saw Acetous wither when the cornucopia was ripped from his head by Hercules; they saw the twelve Aesir and their Agrarian heaven-home turned to mist when the Vikings took up the cross; they saw Harriman dwindle and die when the ancient Persian empire was overrun; they saw Algoma Naomi, the "Mother of Mind," lost to men when the Conquistadors brutalized the Mayan religion; they saw Ama-Terasu, the Japanese sun goddess, go up in a nova of light brighter then the sun from which she took her name, on a special day in Hiroshima; and Amen-Ra, and Anaitis, and Anath, and Anshar (and Kishar), and Anu, and Anubis, and Apollo... all of them shimmered and became insubstantial as their temples were replaced by rubble.
Volume after volume of sacred books of gods.
And that's only the "A's."
As the time passes for men and women, so does it pass for gods, for they are made viable and substantial only through the massed beliefs of masses of men and women. And when puny mortals no longer worship at their altars, the gods die. " ~

In addition, he shined as a story selector and editor; his two collections of others' stories, DANGEROUS VISIONS and AGAIN, DANGEROUS VISIONS have never been surpassed.

My vote was 'other' for Michael Moorcock.  My favorite since age 11 (now 25).  Astounding stuff really, especially taken as a whole.  I just re-read my entire collection of some 50-odd books and the effect was amazing.  A very interesting perspective-building experience.