Over at Cracked, there's a pretty fantastic rundown of all of the science fiction plot mainstays that came from one terrible book: Edison's Conquest of Mars by Garrett P. Serviss. Including ray guns, a spaceship with a working airlock, spacesuits, and epic space battles.
As Cracked explains, "A good chunk of modern sci-fi actually comes from a book that was ignored in its time for being poorly disguised fan fiction." Serviss' book, in essence, is an unauthorized sequel to H.G. Wells' War of the Worlds in which Thomas Edison goes to Mars and kicks some Martian butt. It's a pretty fantastic read. [Cracked.com]