Bodies in Motion is a reference library of over 1,000 images of dynamic poses. Each action was captured at 10-frames-per-second allowing for any artist to resolve issues they may have with a certain pose. All of the poses are perfect for sketching and can be used for many other needs dealing with poses.
There are actually over 30,000 images shot from different angles with varying body types, however they can only be seen if you're a subscriber to the site.
Don't let the title fool you, this site is perfect for figuring out certain muscle groups and planes of the body. There is great reference for different angles of body parts such as the ears, mouth, hands, and feet as well.
Both offer plenty of references of the body that I hope you all enjoy!