A.
If you are trying to avoid plastic, you probably also want to avoid aluminum. I'll leave you to do your own research there. I have a Foogo and it has not leaked on us. Yet, that is. I have not had it a month yet. I also have a Klean Kanteen which has not leaked on us:
http://www.reusablebags.com/store/klean-kanteen-stainless...
It's on sale right now, too.