I hear ya, old armor sets are so much fun to save and come back to
Dungeon 1
T2 full
T4 full
T6 Full
T8 Full
T10 also full (theres a pattern here...)

I also have Gorehowl in there for lore, Linkin's sword cause the quest was so epic, and a Judgment crown with original Zul Gurub head enchant. Plus at least one item from every holiday event. Worse, i normally have one bag on my character at all times full of "Toys" like the gnome amulet from ZA, my skeleton guitar from kara that one halloween, my 3 minute bearman wand, iron dwarf tankard, fishing trophy that makes me a fish etc etc.

Tradeskill items pretty much get stored on alts, the bank is for souvenirs. This practice started in Everquest with Inquisitor Seru's unequipable godly sword.

Same here, I have T5-T10 and some of T2

also some random wepaons here and there, like the arcanite ripper (who wouldn't keep that?)

My bank is full of nostalgic stuff lol

I trashed my T6 and T10 for space. I have full DS2, T1, T2, ZA set, AQ set, benediction, AQ elementium caster weapons, the AQ badge turn ins and a bunch of other quest rewards/things that can change my character. I use 18 and 20 slot bags because I'd have to store them instead of replacing them (ZA bag, Argent Dawn rep bag) I've also kept every trinket that summons a pet and for a time every unique use item like moist towlette, peon sleep potion and tears of elune. Had to use/trash them when turning in Ravenholdt boxes though :(