Billa

This should be on the Slovak flag.

Billa is a grocery store and you see every other person walking down the street holding at least one of these at all times. One, because people are always at the grocery store. Two, because you have to buy them when you check out, so no one wants to pay for them. Three, because these bags are made of titanium and could hold 5 pointy gallons of milk, I have no doubt. They are worth every penny, er, euro.