My opinion is that they are all masterpieces, one of the greatest series of works ever written. And some of the really amazing ones get neglected. #10, #14, #5, #16, #17, #8, #19 are my favorites at the moment. You really can't rank Chopin's nocturnes in terms of difficulty. By the way, I know #s 14 and 5. I will upload them within the next month or two.
I think the nocturnes he left unpublished should've stayed that way.
If AJ came up with it, I'd have the same criticism of it that I have of much of his recording/stuff