Well - we used to have a refrigerator (in my previous company :-( ) with a good collection of stuffs to eat. Infact whenever we (I) were de-motivated - used to go and pick things from there. Its simple - we practised this method.
Each one of us will give the list of things we need (usually once / twice a month) - example - wafers, tropicana, perk (we used to get the big box), etc and store it there. The amount used to get deducted from our salary (based on individuals list they had provided to the HR). Yes we used to take only things we ordered for.
Apart from that we used to get snacks from our office twice a day along with tea/coffee break. Morning - 2 biscuits and coffee
Evening tea + snacks (that varies every day) - like Keasary, mixture, sandwich, groundnuts, etc (all this was company provided)
I would suggest you this:
You may want to consider Lemon- Iced tea powder
pringles / lays
wafers / chocolate box
corn??? why not!
tropicana / real / saint ;-)
corn puffs
biscuits - good day / milk bikis
an occasional pani puri,..