This question gives me so. much. anxiety.

But here I am forcing myself to think about it.
I think it would depend on either the mood I'm in the day I have to choose or the circumstances I'd face with that one bag.
If, on the day I had to pick, I needed an emotional support handbag, I would probably choose one of my Artsy bags.
If I knew I would mostly be going out with this one bag during non-winter seasons, probably my Onthego MM silver floral.
If I needed a big, versatile bag that can be a workhorse but also feels super luxe in that quiet kind of way, I would probably commit to an SC Bag MM for the long haul.
In a
zombie apocalypse, where I know all the cute and delicate bags will eventually be toast (it would hurt to see zombie guts on that gorgeous Artsy handle, for instance), I would grab the very versatile Neverfull GM in damier ebenes.