Like the other members posted, what is your intended application?

Right now there's about 3 Nalgene bottles, two flats of 0.5L spring water, two Platypus 2+L collapsible bottles, a Platypus 0.5L collapsible bottle, a couple of 1 gallon spring water jugs, a Camelbak 70oz. "Unbottle", and a 5 gallon hard plastic water can floating around my place.

Each one has advantages and disadvantages over the others. The hard plastic bottles, jugs, and cans seem better suited for shelter-in-place or vehicle travel. The collapsible bottles and Camelbak are easier to transport when empty and don't take much space. The Nalgene bottles are practically indestructible and work great outdoors or rattling around in your pack.

Just depends on what your needs are.