Lungs always. No animal goes far without breathing and they are bled out internally when you get to them. Head shot, 100 yard walk, heart has stopped beating so worthless to cut the throat, carcass bleeds forever, poorer eating experience all around.
Could never understand shoulder shots either, have had a hunter shoot a big moose in the shoulder, broke the leg, I trailed him for three miles and shot him in his bed ( with a head shot ) There were no vitals touched inside the body cavity.
Each to his own.