Behind-The-Neck Presses 

Here we train the front and side deltoids there's also a benefit to the rear delts. This also involves the triceps as well.

Implementation: You can either do these presses standing or seated, the Later is a stricter movement. (A) Lift the barbell overhead and set it down on your shoulders behind your head. (B) Press the weight straight up and then lower It again, slowly and with your elbows as far back as possible during the exercise.  Make Sure you have a spotter on this exercise, since it can be awkward.  This is definitely A favorite of many hardcore bodybuilders because of its ability to incorporate all 3 Heads of the deltoids so effectively.