Sun's fridge info has helped me better understand the chemistry involved with storage. I believe we are getting to the true answer for long term storage. Fridge or freezer seems to be not recommended. Cool, dark, dry seems to be best. Flavors will hydrolyze to nasty products, and the cold will enhance water absorption, and thus hydrolysis reactions.
A sealable box (tackle box) with a desiccant, like the drying packs in vitamins, in a cool place, looks to be the best way to store all juices.
So it looks like flavored juices will go bad first, and unopened unflavored juices may last several years if stored properly.
See the thread for chemistry details. I am more than open to further information or criticisms. We all want our liquids to last as long as possible, and we are all learning here, especially me!
Kurt