Arthur.C.Clarke is probably the world's best known and bestselling science fiction writer. He has won innumerable international awards for his fiction, for his science writing and for his inspirational role as one of the chief prophets of the space age. If you haven't seen a 2001: a Space odyssey, then you really should. And if you don't understand the movie, than read the book, which is much more comprehensible.
Another book I read from his is the Other Side of the Sky. A collection of short stories originially published in 1958.