Something easy to read at night that gives GMT time. I think at the top and bottom you have the Rolex GMT/Explorer II (big bucks) or Steinhart GMT Ocean 1 ($540) - for you guys that want to have a "no regret" night at the Bush Bar. I've heard the Omega GMT is a nice too, priced somewhere in-between.
I use the GMT function and date calendar - saves the look of befuddlement from the fire-guard when you start the wrong engine that day.
20 years ago all the Europeans had Breitlings and all the Americans had Rolex. My Breitling Navitimer had one of those slide-rule thingies that my eyes stopped being able to read about the same time I was able to afford one.
Don't get a leather band, they rot out in short order in the tropics. I've always had metal, but have seen some pilots with the black rubber diver strap. Maybe someone can post how comfortable those are.
Any other functions are triplicated on the average instrument panel these days, especially with a modern GPS/FMS.
Malabo