One of science fiction's greatest writers, Clifford D. Simak is best known for his classic novels and short stories: All Flesh Is Grass, Way Station, Ring Around the Sun, Goblin Reservation and A Heritage of Stars. His sci-fi magazine articles, novels, anthologies and short stories have garnered him several awards, including three Hugos, the Nebula (and the Nebula Achievement Award) as well as the Grand Master lifetime achievement award from the SFWA, and the International Fantasy Award (1953). I believe he is the only author to ever win both the Hugo and the IFA. Aside from his science fiction works, he was also a respected horror writer, winning the Bram Stoker Award for Lifetime Achievement in 1987.