If I could have only one shoe, I would ask that it be a graceful cordovan colored oxford with a bit of brogueing, like the Vass Old English II model in the photograph. For the oxford is the best shoe for suits, and, in colors other than black, flexible enough to wear with odd jackets.
In place of black I find myself wearing cordovan (the color rather than the eponymous horse leather) much of the time. It has black overtones that are dark enough to be conservative while still leaving the eye something to interest it.
Style and color being settled, the amount of brogueing as the critical question. Too little and the shoe is boring. Too much is too casual a look. A line of punches across the toe and a bit of side decoration is just about right.
If I could have only one shoe...