A water bottle is something everyone should own. In the simplest form an old soda bottle will do, but it's probably better to purchase a good solid fixed cap canteen.

Plastic or metal?

Plastic canteen

Your standard plastic canteen is a solid choice: cheap, won't weigh much and has a long service life. Its only weakness is a poor resistance to fire, so if you manage to freeze the water, keep it some distance away from the campfire. Naturally you probably shouldn't pour boiling water in a plastic canteen.

Aluminium bottles

Aluminium canteens were the standard before plastic was common and these are now coming back. Your water will stay odour-free and fresh in an alu bottle. Although you can warm these up near the flame in case the water freezes, you shouldn't expose it in direct flame.

At some point aluminium canteens received flak as they allegedly caused Alzeheimer's disease due to aluminium mixing with the water. True, aluminium can't be good for your health if digested, but if you don't misuse the bottle, there's no risk either.

Stainless steel

A steel canteen is the most expensive type of container, but arguably the best too - it can be heated on flame and it's very durable and odour-free. These very randomly available form Varusteleka. As a nice drop of information the Finnish army once developed a stainless steel canteen and manufactured it in reasonably large numbers. Must have been expensive.