Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Sculptris - Sculptris: Enter a world of digital art without barriers.
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.
ShapeShop - ShapeShop is an advanced and professional 3D design and modeling application that comes with an easy-to-use and user-friendly interface.
Autodesk Maya - Maya is 3D computer animation software with powerful modeling, rendering, simulation, texturing, and animation tools for artists, modelers, and animators.
meshmixer - meshmixer is an experimental 3D modeling tool for making 3D mashups without too much hassle.