This post might sound like it was written by someone Fussy and Nit-Picky!  Not by an Easy Going person like me! (Ha) Or, you may wonder if there is any value or point in discussing "The Shelf Life of a Banana?"  Probably not a lot, but I'd just for the record I would like to state my personal opinion.  
It appears that some people will actually eat ANY BANANA and lack any discernment! On the other hand, I can't EVEN IMAGINE eating a Banana like #7 (see photo).  Unless it is baked into a loaf of Banana Bread.  Unripened bananas OR bananas with ANY visible bruising; neither work for my palate!
For me, there is about ONE DAY in the Life Cycle of a Banana that I consider it edible. Too green and they leave a bitter aftertaste; too ripe and they're like a mess of baby food goo.  Either which way, it's a very Narrow Window!
Based on the picture I would eat Banana #3 with #4 as a possibility!  With all the advances in the world; global satellite systems, sending men to the moon....amazing stuff; you would think that someone could design a banana that had a longer PEAK!  Isn't there a Bananatology Brainiac who could develop a banana prototype to increase their "Prime" Time? This might be an untapped market that could increase banana sales by millions!  I know I'd personally buy (and EAT) more bananas if the window I could enjoy them was extended!  Can you see why Watermelon is my BFF fruit?!