I know I use the term "favorite" way too much, but man, I just gotta do it again - definitely one of my favorites!

This is a quart and I know of two others, one in quart and one in Half Gallon.  It's a very early jars, perhaps going back to 1850 or so.  It's hand blown which is really rare among jars and pontilled on the bottom and unembossed like many of the early jars.  It's got a beautiful blue color which is heavily accented in the lip due to the wax sealer channel.  I got it on Ebay and the seller had obtained it from a farm auction in New England.

For beautiful, crude simplicity this jar stands alone in my mind.  The closest that another jar comes is the blue Willoughby but this handblown wax sealer channel beats out the Willoughby stopple on that one by a nose.