I use a stainless steel bottle that I got for free from my previous job - possibly the best thing that came out of that job tbh, as it’s light, big and has a stainless steel lid too, so it’s super durable and eco-friendly. Prior to that, I’d use a glass bottle which also doubled up as a tea-infuser, only problem with it was that it was heavy.
#Avoid plastic, even if it’s recyclable or reusable
Plastic bottles tends to leach toxins into water over time - even the so called reusable and durable ones too - and the longer you use it, the more toxins it releases, which can cause inflammation to eventual organ failure or even cancer. Avoid plastic.