And the stupid answer?
One that is accurate. One that has a high contrast ie something like white hands on black ground with white numerals.
An analogue watch is better than a digital (until you really know what time is) as you can see the hand positions more easily than you can work out the time difference on a digital. On a digital there is no visual difference between hh:01:01:01 and 01:03:59 and 01:01:59 and 01:03:01 as you need to calculate that one is 3 minutes and the other is one minute.
You do NOT need a date function nor do you need a stop watch function. The look good but you don't need the date in flight and you won't have a hand free to operate the stop watch. And no bezel; you want as much of the face to tell the time and no fancy metal bits simply making the face smaller.
Citizen, Pulsar or Seiko are all good.