Prior to Nazi Germany's occupation of Europe (especially France)? Italy's air force, and France's ground force.

This might sound ridiculous, but give it some thought: The Italians were the first to embrace a structured air force, and were the pioneers when it came to strategical and tactical bombing. They were also the first to employ torpedo bombers en masse.

Their aircraft, however, were obselete some time after. The mostly wooden hull of their S.M. (Savoia Marchetti) were fragile, and fighters were generally under-equipped after some time when 20mm cannons and tougher hulls became the norm.

France's ground forces were well organised and structured, with powerful heavy tanks to support them. It is no surprise that the Germans employed a lot of captured French tanks during the war. I could be wrong, but i believe that the Germans even tried to produce french tanks even well after the occupation of France. The main weakness of the French, why they lost, is their belief that they should pursue a doctrine that they became accustomed to in WW1, which is exactly why the blitzkrieg was so efficient. They had all the resources they needed, but they just didn't know how to repel the unique strategy of the German Blitzkrieg.