Backbends are known for stengthening the back and stretching the front side of the body. They are also great for strengthening the hamstring. Cobra or upward facing dog is nice warm-up pose for deeper backbends.
Matsyasana - Fish Pose- works neck muscles and gives us our awesome abs eventually! Passively lengthens the muscles of the collars as well as the pecks. Focus on the abs while breathing for the most benefit from this pose.