I was at a loss on how to discover what commentary was the best one for each book. Even my smart friends would not know what were the best commentaries outside of their specific fields. Then this morning, I randomly ran across a site through searching on the Tower of Babel, of all things, that answered this problem.
BestCommentaries.com
At Best Commentaries, they have the commentaries sorted by the book they address along with user ratings for each book. They can also be sorted by academic level: pastoral, technical, devotional, or special study.
Now the system is not flawless because it is based on user reviews and some unscrupulous commentator could get all of his friends to give him a good review like I did with Isaac's Jones Soda photo years back, which catapulted him into the top ten for weeks. And there is the hazard of people giving reviews who just like a guy but do not really know if his commentary is worthy of a good review.
I notice that Paul Kissling's Genesis (The College Press Niv Commentary. Old Testament Series)
Anyway, this site is a step in the right direction. It probably does not save me from emailing a few friends and asking for reliable commentaries, but it will help.