We do have some Klean kanteens-- I do love them! Just tried the contingos for ease of the kids opening and closing themselves in school, as my oldest was in JK and I wouldn't be there to open it for her. They, unfortunately, didn't last long enough to worry about bacteria in valves or straws
  Great Advice

Hey there. I saw your search for water bottles. We use klean kanteen. They are not easy to open, but never leak. And because they are metal, they don't change the water flavour and last a lot longer! Plus, no straw and other valves to clean, so you never wonder if theres bacteria hiding in them. Totally worth the price!