like daniel, one of my favorite teas is taiwan's kao-san. thanks for reminding me, daniel - i haven't had a cup in a while - i think it's time.
i also love mariage freres' marco polo tea. marco polo tea is a black tea that is fruity. i love the complexity of flavors. and if you have the pleasure of visiting one of the mariage freres tea shops in paris, you can try their red marco polo tea (afaik, red marco polo tea is only available for consumption in their tea houses).