147 and 112 are the best and deepest divisions in boxing. Too many great matchups to go around to make anything else the wrong answer. Plus, I'd personally rather watch average flyweights/welterweights than great heavyweights.
obviously talking about the current lightweight division... Linares, Bey, Flanagan, Perez are the champs... its gotten a bit better recently but its still one of the more weaker divisions in boxing right now