Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Sculptris - Sculptris: Enter a world of digital art without barriers.
ZBrush - ZBrush is a digital sculpting and painting software solution.
ShapeShop - ShapeShop is an advanced and professional 3D design and modeling application that comes with an easy-to-use and user-friendly interface.
3D-Coat - 3D-Coat is the one application that has all the tools you need to take your 3D idea from a block of digital clay all the way to a production ready, fully textured organic or hard surface model.
Misfit Model 3D - Misfit Model 3D is a 3D model editor that basically operates with triangle-based models.