Named items.
Ammo, I trip over enough of it that I have 5000 rounds of each type by end game.
Health Stuff I never use all that often, or at all.
Money, well local economy of every location, including The Pitt and Point Lookout are dependent on me by 10th level. Whenever I need new supplies, I just take an Enclave Power armor out of the closet and use it for coin. I've even handicapped myself a few times by making Bottlecap mines. Can't find enough cherry bombs in the wasteland however.
I tend to go really stupid just to get a named item. "Wot? There's a Gatling Laser inside the Deathclaw sanctuary? It's called Vengeance? I'm there!"
"The Break is in Paradise Falls? I guess I'll cold blooded murder all of these fuckers to get it."
Wow, there's a special medical power armor in another Deathclaw infested area? Where did I leave Fawkes and my post Broken Steel Dogmeat?"
Other than that, I do the hoarders thing and gather enough items to get a small insurgency going. Which is how I see myself Post game, doing the Fallout Tactical RPG simulation. I'm going to have one hell of a retirement going knowing that most of the East Cost is mine to control. Although the Collective, or whatever that science loving robot slave culture might be the biggest challenge, I can use my BoS connections for a few vertibirds.