This one isn't fancy - but I wanted the slimmest wallet possible. So I went with the
SlimFold wallet.
Their original one was made out of simple Tyvek paper. My wallet, when filled with cards - is still slimmer than an empty leather wallet.
They don't last as long as leather! Every 5-6 years, I buy a new one. I haven't been able to find one as capable and as slim as these.