What is the most famous AFL/VFL number of them all ?

Yeah it would have to be 5, so many good players have worn that number, most of which you have mentioned (Chris Judd also wears that number at Carlton, as does Sam Mitchell). I also think 23 would be up there (Dermott B, McLeod, Franklin etc). Im sure there are quite a few more big name players to have worn 23, i just cant be bothered researching it.