Can't go wrong with CamelBak
This little device saves its hydration reservoir from potentially causing a lot of havoc and frustration. It stops water from leaking all over your coat and freezing into an icy addition to your outer layer; it also saves you from losing precious water during the hot summer months. If you pack your car like I do, it stops water from being squeezed out of the bladder that is crammed into the last space available in your trunk.
If you like your water to stay where it's supposed to, get the Ergo Hydrolock and never deal with H2O sneaking out of its home.