I like to place my shot right in the rear crease between the shoulder and the body. If the shot goes a little back it still center-punches the lungs and if it goes a little forward it breaks the shoulder. Keep in mind that deer a very rarely perfectly broadside and in this case I try to stay as close to this shot as possible while breaking the back shoulder. If you decide to start busting shoulders every time, make sure you are using a well suited bullet.
Ignorance is bliss...unless you're aware of it.