Well, far be it from me to offer a definitive definition, but I know it when I read it. It’s usually near-future distopian literature with some cybernetics and some punks (ie hackers). Virtual Reality, the net, feature large in most cyberpunk.
To put it in movie terms, Blade Runner, not Star Wars. Brasil, in which I’d contend DeNiro plays one of the first cool hackers ever featured. Even 5th Element has some cyberpunk elements. Star Trek does not.
The wikipedia article has a lot of great background and author shout-outs, but even though Bruce Sterling is mentioned, one of my perennial favorties is glossed over, Mirrorshades. Everytime I’ve got spare time in a bookstore, I search out a copy of this 1988 classic to remind myself who that first wave of cyberpunks was: Sterling, Gibson, Bear, Cadigan, Rucker, Shiner and others. Then I start tracking down their recent work.
My favorite cyberpunk novel? Oh please, how can I not say Neuromancer. But really I enjoyed Idora and All Tomorrow’s Party just as much. Sterling’s Heavy Weather, Bear’s Slant. I’ll have to sit longer than a few minutes at lunch to post that!
My next potential post: Can Space Opera be Cyberpunk? There’s a lot of distopian sf out there and, to me, cyberpunk is usually more immediate or just-around-the-corner than most space opera is. I agree with Enok’s first post, it’s usually “earthly.” But elements are definitely showing up in the larger scifi genre.
But for now I’ll have to work on beefing up this post!