My bags and bank are filled with junk and sentimental stuff. Atherya's is more like a wardrobe. I have a load of archaeology fragments and solved items, lots of random items from Winter Veils past, items that Koruth made for me, and, in some cases, profession-based items like ores, old gems and other things I forget to throw out.
These are my favourite items from each of my characters' banks:
Spinegrinder: Spectral Essence
Kharzil: Skull of Gul'dan
Daeaye: A letter from Koruth
Atherya: Fras Siabi's Cigar Cutter
Sevacia: Olaf's Amazing Handkerchief