Casio G-Shock Black LCD Tough Solar Atomic (GW-M5610)
This is the ultimate in zero maintenance watches. As a solar watch it'll never run out of juice, and it gets the time accurately updated every night from the atomic clock radio sync signal that I think is in Colorado. So, it's never off by more than.. well, I have no idea how close it is to pure atomic time, but it's probably better than any other clock you'll own.
I wore this a handful of times, but never really made it a regular thing, so it looks brand new.