I'm pretty sure most gamers have the hoarding issue, especially older-ish ones. There's been a lot of stuff over the years that trains you hard to loot everything to the ground and never let go of anything whatsoever, while simultaneously never really being difficult enough you need the shiniest of macguffins to save you. So you compulsively collect them and never use them. It's a vicious cycle.*
... in any case, I think about the closest thing I have to a persistent quirk these days is naming characters something traditionally inflicted on their opposite gender. Not an always thing, but... very common. At my laziest I default to naming guys Jill and ladyfolk Jack. It's a hobby, I guess.
Second closest would probably be a fairly low bar (at least relative to when I was younger) for deciding to slap a game in the face with a twelve inch cheat engine. Memory editors have made that sort of thing so much easier nowadays, so if a particular feature annoys me in a game I otherwise like, I tend to just... fix... the nuisance factor.
*E: ... that said, did you know you end up with around two or three thousand gold if you vendor everything in morrowind's starting town? Because you do. Strip enough houses of their cutlery and pillows and it adds up.
E2: though that did remind me, there is a third notable I can recall. Occasionally I'll fixate on a specific item or category of items, and either hang onto one forever (Voidspire Tactics was one of the more recent ones I played through where I did that) or collect basically every one of them I encounter. Elderscrolls games are easily the most prominent offenders on that front. I compulsively loot every light source I can find, because for whatever reason it amuses me to filch a lantern from behind a guard while yelling something along the lines of, "I am the thief of light!" in my head.
Well remember one time I took the time to do it and absolutely blanketed a building in purloined lighting. One of those shacks in the starting town, iirc. Every available surface had lights on it. Roof, encircling the building, everything you could stick one on inside. Torches, lanterns, if it glowed it was included. It was a good run, that one.