I use ammo for barter. Buy the shipments of every material a vendor has, and pay with ammo and drugs I never use. I have no use for .38, .45, 5mm, missles, 10mm, .50 cal, flamer fuel, or mini nukes anymore. I use .380, 5.56mm, 12ga. and energy weapons. Most have multiple types of damage.
Used drugs early on, but long since dispensed with any need for their assistance. Only reason for caps beyond shipments and fusion cores, is building stores for settlements. I rarely buy anything else. I have 90 or so fusion cores now.
10 sets of power armor at this point. A couple are cobbled together. I will probably start buying every frame vendors have, and set those up. I use the 45f the most, since I only need steel, and for the torso, circuitry, for repairs. I have the perk for double life on the cores as well.
My latest goal is getting the perk from every companion. The backstories on each, and sleeping with all the girls. I cannot see me finishing the first playthrough in less than 300hrs. Heck, the expansion may hit before I am done.