Water jugs that is. I tossed my trusty Reliance 7 gallon water jug
http://relianceproducts.com/consumer/product/11.html
It started leaking on the bottom, it was old, so I chucked it. I want to replace it but with something a little stronger. It was nice because it held more than 5 gallons, had a valve on it and was thick plastic. What I don't want is something that is thin or square. I liked being able to slide it in between things in the cargo area. The short square ones have a large footprint and are hard to put on top or under other cargo. I also want to stay away from metal cans.
So what do you suggest? I'm thinking that because of my constraints and small cargo area I may end up with a collapsable. I just don't like how floppy and weak they are. They also tend to have a chessy and cheap valve on them.