Depends totally on the situation, animal angle, weather conditions, range etc. Personally I like a neck shot on anything out to 150m if lying prone, confidently take a neck shot out to 100m free standing, headshot within 50m, but will generally opt for a shoulder shot on anything past those sort of ranges. The majority of the deer Im shooting these days, on average about 5-6 a month, Im shooting with a 223, so more careful bullet placement is needed. I never aim to hit "heart and lungs, they're "behind" the shoulder. I hold on the shoulder in an effort to smash it, and everything behind the shoulder blade. An animal can't run far with no front wheels, and often the shock of a shoulder shot will drop the animal on the spot. If shooting down on an animal aim to send the bullet through the spine, between the shoulders. Pole axes them.