I use a combination system to have as much flexibility as possible. I have several 5 gallon containers that I keep full and change out the water every 6 months or so. I also buy 1 gallon “milk” type jugs of drinking water from the supermarket that I normally drink my water out of and I also keep a few of the 20 oz bottles that are easy to handle and are tough enough to carry around with out leaking. I also use my old soda and juice bottles to keep about 20 gallons frozen in my deep freezer which gives me water as well as keep my freezer cold longer during power outages and makes it cheaper to run day to day.