started out as author of sf short fiction. As novelist his first great success was Ender's Game (1985) that won both the Nebula and the Hugo Award. Its sequels kept the high standard he had set: Speaker for the Dead also won both awards. Another series is set into an alternate world with fantasy elements: Tales of Alvin Maker.
-> Orson Scott Card booklist
is a very prolific author who writes both fantasy and science fiction. Most of her sf novels are set into her Union-Alliance universe. Two of them, Downbelow Station and Cyteen won the Hugo Award.
-> C.J. Cherryh booklist