"You are what you eat" -- and drink -- and we get exposed to a lot of plastics. Gifted with a plastic water bottle from my company, I pondered then googled its plastic information: 1 pete water bottle. Some results follow:
Less Leaching Plastic: #2, 4, & 5
More Leaching Plastic: #1, 3, 6, & 7
(The above with good information from Bonnie Penner posted at PattyCake.ca.)
The same article stressed not reusing commercial water bottles, advised not heating the plastic, and reminded that if you taste the plastic, you are drinking the plastic. (Makes me want to check the Brita Pitcher and a few other water bottles and thermal coffee cups to see if they are the less leaching plastic.) Stainless steel is best.