I've changed my philosophy on everyday watches over the last couple of years as society gets ever more casual in dress. Before I'd try to get the dressiest looking yet sports watch that I could find. The above mentioned OP39 would basically be the absolute epitome of my old thinking.
Nowadays, I prefer an everyday watch to have some useful "everyday" complications, as it's a watch I'd wear frequently. A date would be a near-must, and an additional complication or some kind of timing mechanism would be great.
So my first pick for OP would be the Omega Seamaster 300M with white dial. Works on both bracelet and strap (heck a lot of ADs will throw in the strap).
If a GMT is more your speed, I'd consider something like the GS Mt. Iwate dial.