That said, until recently, I'd have answered quickly and confidently. The 5980/1A and 5650G. This may strike some as strange. Isn't there a significant gap in situational coverage? Business? Formal? In truth, in my experience, no it does not. I've spent years in board rooms, meetings, even the occasional black tie event with none other than my trusty 5980/1A on my wrist. We literally did it all. No mess, no fuss, no unwanted attention. And with a significant lifestyle change some years ago the degree of formality, of any type, in my life decreased considerably. These two work perfectly for me. BUT
With that written, I'll throw a curveball. As of this exact moment, I'm officially changing my go-to-two. Why? Simple, my wrist found my 5204P. Normally too formal for my everyday tastes (see above), I've been experimenting with context and environment with the 5204P and it is absolutely singing. It's a combination of so many attributes, yet remains so discreet in 99% of life, I'm really finding its stride. So the 5204P is now in, but joining what? Complication and function, not environment, are driving the decision of its pair and the finalists are....damn, I shall not even try. 5650G. And I'm a Nautilus guy through and through, but in the pecking order there isn't an Anniversary, QP, Flyback, DT, moonphase, or time and date Nautilus on earth that can permanently supplant the King Aquanaut...for now...