Read em all. K is the best, and Snow Crash is really quite amazing - my mind was boggled for a while. DA was fun, but not nearly as mentally stimulating.
The first book in the trilogy, Quicksilver, is allegedly a prequel to Cryptonomicon and deals with alchemy. There is some speculation that the "mystery of Enoch Root" will be solved in this book.
I thought Kryptonomicon was extremely well written, although I didn't particularly enjoy the way he continued his right-ward drift that became evident in Diamond Age. In general, he's come a long, long way from the guy who was ripping John Silber in The Big U.
First of all, my first experience with Stephenson was Zodiac, which is very nearly a Green Peace fantasy, very anti-business and continuing the more general anti-establishment perspective that The Big U showed. In The Diamond Age, those attitudes are more or less gone. After, the neo-Victorians? I also remember reading a review in on of the SF monthlies (F&SF, maybe) harshly criticizing Stephenson for his political shift. Also, the Diamond Age often felt like an excercise, as if he was mostly concerned with building up his literary muscles. On the other hand, if that was the case, it paid off in Kryptonomicon.
**note, mild [r] below on the above title** Just finished it, and recommended it to my step-father. I thought it was well written, funny, and techincal without being the unreadable pain in the SS clancy can be sometimes when he gets off on a 19 page rant about how to make a nuclear weapon out of toaster parts (Sum of all fears). Though, it was nerdy in things I'm nerdy about (history of computers, etc), so maybe I dug it on that basis in a way others wouldn't. And the Math was light enough that I could get through it, even if I did skim a little when the breakdown of the Zeta functions started giving me calculus flashbacts I wasn't comfortable with. I'm interested in quicksilver, and will likely read it. Especially if it explains the Enoch Root mystery, like how an 85 year old dead guy can traipse around the jungle in the Phillipines inbetween moving in and out of Jail on a whim. Also, if there is less Qwghlmian dialogue, cool, because those were some ridculous combination of consonants. And I though NYC Cabbies were in desperate need of vowels...crimminy.
Five Year Bump! I'm reading Stephenson's latest, Anathem -- it's awesome. It starts slowly and takes some getting used to because of the made-up words and language (similar to the book version of "A Clockwork Orange," there is an appendix for all of the slang), but I'm about halfway through and (a) I don't want to put it down, and (b) I don't want it to end. Highly recommended -- up there with Snow Crash and Cryptonomicon as the best stuff I've read from Stephenson.
Damn you. I was debating on going to a reading and signing he's doing tonight and now you've sold me on it.
I'm fairly sure that some of these posts are just strings of randomly generated words from a program called "Stephenson," designed to tease the rest of us who don't get it. Especially posts 3 and 4.