I use a half gallon insulated metal water bottle/jug and it's incredible. I love it so much, and I couldn't go back to even a normal sized one. I drink easily a half gallon a day now. I'm about to upgrade to a 1 gallon, because the lid on my half gallon is difficult to open, and the 1 gallon has a much better lid. I know it seems ridiculous, but it made a carry bag for it with a strap to wear almost like a messenger bag. I can carry all my shit and get hydrated at the same time. So fantastic.

Also, buzio is the brand on Amazon (I know. God, I know, but we don't have a lot of options where I live. If anyone knows a better one, I'd love to hear it). They're great. Everyone in my family has one in different sizes