Rigify: Modular Face Rigging

Mechanical Rigging in Blender: Battle Mech

Rig a Skeleton with Blender and Rigify (Video Course)

Game Rig Tools (Blender Addon) - game-ready rigs in seconds

Rig Anything With Rigify - Auto Rigging in Blender

Lips Detail Alpha Pack (zbrush, blender, 3dcoat, substance)