so many of the great houses in the early part of the Twentieth Century were focused on these.
JLC and IWC made perhaps some of the most iconic military ones. I have a weakness for the Zeniths as well - and the odd Breitling. LOL.
While Longines is perhaps one of the most exciting innovators of them all, Minerva, Omega, Breguet, Universal...
To collect the best pilots watches from each of the manufacturers would be a great theme.