I went with mostly 0.5L bottled water. Sure, it can get somewhat expensive. But I try to buy in bulk from Costco
I actually have around 20 cases of the 1 liter bottles for emergency drinking that I rotate at home from Costco.. I also have a few .5 liter cases to fill the cars with when we go out.
Then I have 7 gallon containers (10 of them) with the idea they would be used for non-drinking use.