This idea struck me while writing my other post. What if we had even more control over what effect our shots do? Take 'Sniper Elite' for example. In the title, if you shoot an enemy in the heart, they are dead. Imagine if the same happened in Fallout 4 (obviously it won't be a insta-kill every time but count it as a critical hit). This could be implemented in VATS where not only are we allowed to target specific limbs, but specific organs as well.

Imagine your facing an opponent who is hounding you with a heavy weapon and you can't seem to dislodge it from his hands. Lets also say his Strength is not very high, so you hit him in his knee and bust his kneecap. He instantly hits the ground in pain and it will take some time for him to recover. If he had higher strength he may be able to just stumble and withstand it so he can keep firing (maybe tie it in with endurance). Or another example, they are strung out on chems they took and so they can't feel it anyway (this would be a situation you could pair with Radiant AI).

Another example would be your facing two opponents standing side by side. You shoot one in the leg and he stumbles into the other which makes him stumble allowing you precious seconds to hit them while their down. Or perhaps you hit a Super Mutant Behemoth (which I doubt will return but I'm being hypothetical) and he topples over on some less mutants? The situation where this type of advanced anatomy makes sense is endless and I believe all aspects of the game shine for the advancements.

This could also work more in dept for robots. Perhaps you shoot and cripple their power supply? Could cause them to simply lose power to their guns and emergency power keeps them moving, or results in critical failure. Since they are more so intact, you get more parts. Maybe you blow off a leg and they topple to the ground in hilarious fashion still trying to kill you as they get up? This could also affect perks. You get the robot expert perk (i believe its what its called) and instead of disabling the robot, you could set it up to explode in spectacular fashion taking out its friends with it?

I think head shots should have a bit higher critical damage bonuses, for most humanoid npcs/enemies they were pretty good but enemies like super mutants and other bullet sponges could take way too many shots to the face.

Yeah, Super Mutants could take a butt whopping and keep on ticking. They were built to be that way though, but if you shoot something in the head, it should go down easier than something shot in the foot.