Camelbak military version would be my second choice, their new civilian models are paper thin
If you are talking about one with a drinking hose, I've been using a Source 3L with insulated hose for a number of years with zero problems (knock on wood).
Israeli military take their hydration seriously.
http://sourcetacticalgear.com/10-reservoirs
I've been using the same military Camelback 3L for the past 9 years, just have to change out or lube an o-ring every now and then. Sure wish I'd bought a few of these back then as they've changed them and I don't like the new ones as much. Mine is simple and tough, and my filter plugs right into the drink tube so I can fill it easily without opening it.
Leaking past the o ring is my only complaint with camelback.