What You Know Him For:
Neuromancer, Johnny Mnemonic, the abstract concept of the Internet
William Gibson wrote Neuromancer, the novel that basically started cyberpunk. If you think you haven't been influenced by the book, check again, because you're using the Internet to read this. In a very loose, abstract way, Neuromancer predicted the rise of the Internet. It was the first work to present the online world as a massively influential, interconnected, always-on entity. And all this at a time when the real Internet was a handful of nodes restricted exclusively to military nerds.
If your confused grandparents have ever asked you, "How do I navigate cyberspace? Is there some sort of ship or capsule?" you can thank Gibson. He first coined the term "cyberspace" in Neuromancer. But his more prophetic work is almost completely overlooked. Nobody pays Idoru much attention, probably because it's a much-smaller-scale book. The fate of the world doesn't hang in the balance; it's just the fate of the alternate media, and a young girl's naive belief system. In parts, it reads less like hard sci-fi and more like young adult, probably because its central protagonist is a teenage fangirl. Idoru focuses not on a grand action-adventure plot, but on the state of the new media, what it means to be a fan, what it means to be obsessed with things that aren't real, and what even is this "real" s**t, anyway?
Neuromancer shot for a future 50 years away and hit the target; Idoru shot for 10 and hit the bull's-eye. It called laptop/tablet/mobile culture, Second Life, and the importance of online social networks, and even got as weirdly specific as the advent of purely synthetic Japanese pop stars. Idoru isn't a badass genre book. It won't get you any nods from the black-leather-trench-coat, Ray-Bans-indoors crowd, but really -- you don't want to hang out with those folks anyway. All they want to talk about is phreaking, and every meal is some weird flavor of Doritos they imported from Japan.