I really enjoyed Zodiac. It’s reads like a thriller novel but it’s a little more grounded and less weird than Snow Crash. I think it’s a good entry point for Stephenson novels.
The first half or so of Snow Crash is a great entry point if the recipient already read some cyberpunk and thought "this has something interesting but also has a stick up its arse, it's about time someone ripped the piss out of it" - and I say this as a fan of Gibsonian prose excess.
The only problem is this puts the recipient in a too-cynical, too-stylistically-demanding mode for the rest of Stephenson.
- Posted on my Ono-Sendai Rig, from some kind of Zone, while experiencing Hacker News as some kind of geometric hallucination, under a sky the colour of a television switched off...
Zodiac is the easy introduction because it's the least Neal Stephenson book of the lot: short, minimal infodumps and tangents, and it really doesn't get much nerdier than the protagonist being a chemist [as well as a wetsuit-wearing crime fighter] or much weirder than there being a metal band in there because Stephenson wanted there to be a metal band.