The Omega Speedmaster has a rich history..
Of particular note is it's selection to be the NASA Extra Vehicular activity (EVA) issue watch..
Read an overview about the tests here:
More NASA Test Info
And this one, which talks about the Omega, Lemania 321; the Rolex, Valjoux72; and the Longines, a. 13ZN finalists.
Speedy, Moonwatch