Baby wipes for sure!
DH always requested those little flavor packets you can pour into bottled water. Also instand cold coffees were good, mini electric razors (I think they're called on-the-go razors or something?), those little packets you break to make mini heating pads that they can shove in their pockets, tuna packets and crackers, toiletries if they don't have a store on base where they are (shampoo, conditioner, body wash, loofahs, shaving cream, deoderant, floss, toothpaste, toothbrushes, foot powder, etc), new clean pillowcases, and clean underwear.
They also enjoyed little debbie snacks, candy, and homemade goodies. He always used those items to trade people for other things he wanted lol.