What lead each country to design their helmets the way they did? Like why does the Stahlhelm look like those coal buckets and the British helmets look like a bowl?
Which design was the most effective in terms of protecting its user from all the different threats of battle? Which helmet was better at which task?
Also, what's your personal favorite? Whether it's the design, history, etc.
Thanks.
This post from a few years back seems to answer your question.
https://www.reddit.com/r/AskHistorians/comments/41u25p/what_was_the_most_effective_helmet_of_ww2/
The germanic sallet helmet which emphasised protection of the neck could arguably be considered the most effective, the concept was later used in WW1 for German troops and developed through to the second world war. The vestiges of the design are still apparant in the modern PASGT armor system.