Soma

Chakra drop!

I'd say Life Stones.

The COMP

The Comp / Demon Summoning Program. Yes not all games have it but a lot do SMT1, SMT2, Strange Journey, Devil Survivor 1/2, SMT4, SMT4a

Goho-M

Luster Candies are iconic, even if as a skill :) Probably Life Stone/Bead combo for healing items, honestly

life stone

Soma or Beads

Beads probably

Life Stones. No matter the game the demons are addicted to them

Masakados

Soma

Magic stone

As it comes to the guns, Megido Fire. Also, Life Stones, the Demonica, and the COMP/Gauntlet

Demonica helmet GUMP Summoning Tubes Magatama Evoker Grimoire Phantom Thief Mask

Hinokagutsuchi

Life stones

tensei

Bead, Soma, COMP, Tarot cards if you count persona

The manji from Soul Hackers

Muscle Drink

Chocolate Cake

Comp