David Brin: The world of David Brin's Uplift Saga is one of my all time favorites. He is futurist whose background predisposes him to writing science fiction, but his unique understanding of humanity and appreciation of the otherness we should find in alien species (or other earthly species) are what truly make his stories wonderful. To learn more about him, take the link at his name to visit his webpage.

Orson Scott Card: This marvelously prolific writer spins moving, thought-provoking and inspiring tales in past, present and future.
His Pastwatch was so outstanding, even my Mother (not normally a sci/fi reader) could not put it down. But my favorite take place in a mythical, half-magical colonial America that never was, but maybe should have been: The world of Hatrack River.

Lois McMaster Bujold: How could anyone not love Miles Vorkosigan? A man whose genious, personal charm, and frenetic drive overcome the seemingly insurmountable obstacles of a debilitating mutation, especially in a society that hates and fears mutants. Bujold's best stories, like the Miles' stories and Falling Free, take our ideas about disabilities, whether physical, mental or socially imposed, and turn them about.