The closest thing to a perfect fighter is Carl 'The Cobra' Froch.

It's true that his defense is lacking but when you have an indestructable chin and body, wasting time taking defensive action only detracts, much like a sprinter would be foolishly wasting time if he was checking that there was solid ground beneath his feet before each step.

A defense is only necessary when your opponent can hurt you, we don't wear crash helmets when we go outside to protect us from flies, simply not necessary.

So, in conclusion, yes the most perfect fighter is Carl 'The Cobra' Froch.