If there could only be one watch, I would go for the classic and simple 5711, in blue no less. Looks good for any occasion, and that porthole harks back to the old sea times.
But on a more practical note, I know that I am one whom loved the classic diver look complete with the uni-directional bezel, and a raised crystal is an added bonus. To that effect, I find the SD4000 to be the one watch for me, on a practical front. I like turning the bezel, and the precise clicks could be quite soothing at times. And without the Cyclops, it looks more balanced like that of the 114060, but better as it has the necessary date complication. I thought of putting the one watch test, to test, all pun intended; and I have been wearing the SD4000 for 2 weeks now, 24 hours a day. Haven't had a peep at any other watches in the winder, and am doing alright. This is one practical watch indeed.