Super Stimpacks, Psycho, XL70, Combat Armors.
SS are common equivalent of caps while trading. You can usually buy loot, offering super stimpacks to seller. Psycho as of it's very common PvP / PvE drug for resistance & strenght enchancment. XL70 as of it's reliable popular hexing smallgun. Combat Armors... becouse everyone wears them. If u get improved crafted XL70 or CA with good rolls it can be worth even 50k.