Updated April 2022: We've added the Yeti Rambler, CamelBak Chute Mag Renew, Platypus SoftBottle, and Stanley Master Unbreakable Thermal Water Bottle. Long ago, people figured out how to make an insulated water bottle that keeps cold drinks cold and hot drinks hot. The design and manufacturing of these reusable bottles have improved so much now that few leak—though some do—and durable powder coatings mean you're less likely to end up with scuffs marks all over the flask. The best of the best have nicer lids and small design flourishes that make them easier to sip from as you tote 'em around all day. Not every bottle is great, but most are still pretty good. Of the nearly 20 bottles I tried, these are some that will hold your water just as well, but they didn't stand out enough to give them a spot above.