John Wayne played so many characters named “John” or “Duke.” So many that I just tried to count how many roles and I lost track. I counted twice and got two different numbers, but I believe my final tally is 39 roles where his character had at least one of those 2 names.
EDIT: Final tally:
36 - “John” or “Johnny”
3 - “J” first initial, no full name given
5 - “Duke”
Considering how many military roles he had, I’m going with Lt. Col. J.B. “Johnny the Duke” Thomas