My guess is that the Mark XI is the most famous one. With the old in-house movement, being in production fo many, many years, it was used in the military in different functions. So this is the one.
Hi Charlie I agree that the Mark XI is the most collectible one. But if we go to the modern Mark, I believe that the new Mark XVIII is really the best. Perfect size at 40mm and I do love the traditional numbers, with the 6 and 9 back where they should be. Additionally, it has the soft iron antimagnetic protection which is highly desirable. I do like the Mark with the JLC movement, but I'm afraid that JLC is not robust enough for a work tool as the Mark is supposed to be.
For the wristwatch Mark, definitely Mark XI. However, that's a mine field when it comes to pick an authentic one with correct spec, especially since it came in several versions.
Don't worry Paul, this is the IWC watch forum, but this is also a place where friendship amongst collectors can be expressed. When I read the great posts here about vintage Aquatimers being restored, old pocketwatches with their stories, when I see people like Clepsydra posting amzing articles... There is nothing symbolic about this post. Only a jeu de mot with a name, no more, no less.
I didn't expect to generate any controversy riffing on Tonny's post. I will say that it is special forum that brings folks together in friendship. BTW..I hold Mr. Fleminger in high esteem also! We have some remarkable "Mark's" here!