what do you read?

Ok, so I have Words for jazzfish, but my brain is not quite in essay mode this week (as analytical functions have been co-opted by the readercon drama, which seems to have sorted itself out, and doll wing design) but I have a question for the masses.

I've been finally putting some effort into seeking out author/reader-related SF/F conventions (speaking of which-- anybody else want to contemplate CapClave?) and they're all full of guest authors I've never heard of. And while I'm entirely familiar with the concept that everyone who reads fantasy has the authors they read and the authors they always see on the shelves and never actually bring home with them, and the people who only have one book at the library and so unless you pick that up you'll never have heard of them (or if you forget that was who wrote that somewhat interesting book you read years ago...) Anyway, one of my goals for the next year or two is to finish reading all the fiction that I kept aside when shelving everything because it came out of my boxes and I hadn't read it yet. And there are a few people who grauwulf recommends I read that we've got in house as well.

But what I want to know is: what authors/books do you think are quintessential? Things that rocked your world, or that half of what you read afterwards seemed to refer back to, or just things that you couldn't imagine anybody not having read. Lists of names are fine, but if you have particular works or "this is why everybody should read this" that's excellent, too. Doesn't have to be SF/F, either, although I will probably be resistant to Russian authors or anti-communist themes since I've had enough of that sort of depressing and it makes me want to rip pages out.

So, thoughts?