I periodically reread stuff by Stanislaw Lem. "The Invincible" and "Eden" are nice novels. "Solaris" was alright, but didn't interest me as much. "Tales of Pirx the pilot" are an interesting read, as are "Adventures of Ijon Tichy".
I also like Ray Bradbury, Asimov, and various other fiction writers. And Tolkien, too.