You should know by now that you don't need to buy expensive bottled water. It's a lot smarter—ecologically and economically—to carry your own reusable bottle. And thankfully, there are plenty of options to choose from these days. You could get any old plastic Nalgene, but you should really invest in a quality container that will fulfill your hydration needs. Here are some of the best ones out there, from foldable flasks and bottles that can keep a chill for nearly 24 hours to stylish glass vessels that use Japanese charcoal to make plain old tap water taste great.