So far I have received several housing items (windows, doors, roofs, and housing furniture such as music stands, eaorzea map, immortal flames banner , etc etc)
The other things I've noticed, Ifrit's Bow from one Retainer and lv70 PVP heavy armor gloves (warwolves i think they're called?). Both came from my Archer on 2 different occasions.

Those were the only items of note. Though I do find it funny that my miner has a trend of coming back with fish.. alot.. HQ fish mind you but still funny