Neck shot. Closer to the head than the body, and between the spine and the esophagus. It should be either an instant kill or a slight flesh wound.
Ah, but there's the fallacy of the neck shot. Sure, you get some spectacular immediate kills (CNS shots always are impressive), but you run your
highest risk of a horrible wound that will never heal and which will likely cause a long, terrible death. Hit the esophagus, and you've just torn out the animal's ability to eat or drink. Infection can and often does set in. With high-velocity rifles, true hydrostatic shock can cause enormous bloodclotting around the area where the bullet hit, which will cause necrosis if the animal isn't put down.
At 100 yards, it takes more than 1/10 of a second for a bullet traveling 3000 fps to reach its target. Do you realize how far a deer or elk's head can move in 1/10th of a second? Several inches, at least. Think
snake. These are prey animals, and constantly lift and drop their heads to check out their surroundings.
Add in your reaction time from when your eye sees the movement to when your brain processes it as a signal to not shoot or to change aim point (Commonly considered to be .25 to .4 seconds, but we'll take the low end at 1/4 second), add in lock time, and you're getting up to 1/3 to 1/2 of a second between the neck/head's beginning to move and your bullet impact. Heck-- in that time, a whole elk could get completely out of the crosshairs at 100 yards, on occasion. (I've had it happen.)
We owe it to the animals we hunt to use the shot that provides for the highest probability of recovery and quick finish. The largest kill target is in the chest. Impact too high hits spine, too low hits the heart. Too far back hits liver (lots of shock and rapid blood loss), too far forward hits shoulder (lots of shock, secondary missiles, and helps immobilize). On a bull elk, you're looking at a target that's about
beachball-sized there.
There are times for neck shots (mostly to put down wounded animals), but as a rule, I don't like 'em.