I really don't like Snow Crash much.

Firstly, it's dated quite badly, since it was written in the recent past about roughly-now. He gets the technology pretty much right, but the speculation about how that technology will change society pretty much all wrong.

Secondly, Mr Protagonist, as a protagonist, annoys me in that he seems more like the kind of character that a fourteen-year-old boy would think was awesome (greatest swordfighter in the world, for no good reason!) than somebody I want to read a book about.

Cryptonomicon, on the other hand, is a must-read. I don't really even like science fiction that much, but Cryptonomicon is a must-read.