Rigify is a Blender Addon that allows users to create animator friendly rigs with nearly no extra effort. It greatly simplifies the animation process!
This package removes all unneeded parts of models made with Rigify. Artists only need to deal with the necessary bones and meshes in Unity, while having the full power of Rigify in Blender.
Important: Rigs generated with Rigify are not usable with Mecanim!
Rigify to Unity Tutorial Video
Unity Forum Thread