
This Seiko sumo gmt is my candidate for a single watch, watch collection. You have the robustness of a 200m dive watch, with the versatility of a gmt complication, with adjustable local hour hand.
Seiko's lume is legendary, and with the solar powered movement, it's a set and forget watch.
The only thing that lets it down is the bracelet. With drilled lugs, however, it's easy enough to swap it for another strap, which was always my intention, so I wasn't bothered by this.
Price wise, it's not cheap, but you are getting a high quality timepiece and I thoroughly recommend it.