Suunto wrist computer (multiple time zones, altimeter, barometer, compass) or a Seiko divers watch (had it for 22 years now, traded in a Rolex for it).

Why? reliability, waterproof, durability and ability to read at night. The batteries have lasted for years in each, so as long as I put fresh batteries in before I am gone for an extended period, I am good.

When in field environments, I generally wear the watches on a breast pocket (through a button hole if there is one) because I hate it being on my wrist.