FYI,

Here's a pretty good review on different types of water containers

Water Container FAQ

After doing a little more research on different forums, this seems to be the general consensus of the commonly found containers.

Desert Patrol containers from Walmart are notorious for leaking. Almost every review I've read about them mentions leaks.

The translucent polyethlene 2.5 gallon water jugs with the spigot are even worse than the desert patrol. The plastics are biodegradable and meant to break down in about a year (some people say months, others have gone over a year), but it seems like it will happen sooner or later

The blue Reliance aquatainers are pretty reliable, some issues with leaks after being stacked on top of another one (specifically NOT recommended by Reliance if you read their webpage). Some people haven't had problems with stacking, some have. I have them and use them for camping, and they've held up well as long as you're not too rough with it. The spigot makes it very convienent.

The clear polycarbonate containers used for sodas and water are pretty reliable.

The military MFC's are really good, but expensive. I might buy a few to replace the Aquatainers that I currently use for camping. If only they had an on/off spigot like the aquatainers, I think that would be perfect.