i keep all of my hus in a padded caselogic cassette tape case:
while its original purpose was to hold maybe 8-10 cassettes, i have repurposed it to hold ~50 hus w/ sleeves instead. all the jewel cases & manuals are kept elsewhere, as this allows me to keep all my games within a small footprint.
i've tried using business card folders/wallets in the past, but they always ended up bowing/stretched due to the thickness of the hus.