I collect various German uniform items, such as insignia, but mostly medals and decorations from both the Third Reich as well as Imperial Germany. I also have one daggar, a Luftwaffe Second Model. I have several visor caps and many, many paper documents including photographs and soldier's letters home from the front.
I also collect U.S. Militaria, and have many uniform sets spanning from World War II to present over various branches. I have some US Medals, visor caps, insignia, and other random US militaria.
I have a smaller assortment of international militaria that I have exchanged with fellow servicemen that I have had the pleasure to serve with. I have traded my insignia for theirs on different occasion and now have insignia from the Royal Air Force (UK), the Royal Australian Air Force, and the Royal Canadian Air Force - all from my time spent with the RAF in England as a USAF person.
Outside of that, I collect whatever strikes my fancy at the time and when it fits my budget - particularly German and American pieces.
Cheers,
Mike