[heitzke]

I'd go with:

Pre-owned: (which is my recommended course of action, watches are all reconditioned and you'd never know. Get one with box and papers for resale)
Watchbox (full-disclosure, I used to work there in product design, they're a great trustworthy company)
Crown & Caliber - owned by Hodinkee and a solid pre-owned company. You'll have to wait to find what you're really wanting

New:
Hodinkee - best new retailer as far as I'm concerned. Great company.

Grey: (nothing wrong with grey, just know what you're getting into. They're all new and legit)
Jomashop - i've also purchased smaller pieces from them and they're great. I just usually go PO for bigger spends.

Also nothing wrong with TrueFacet, RealReal, etc but they're not watch pros. Chrono24 is also fine, but it's an eBay of retailers and just make sure you pick someone with LOTS of reviews and also has a store behind the name.

Full-full-disclosure: I worked in watches for a few years so i'm also very biased, but I do know the majority of these companies intimately.