Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Sculptris - Sculptris: Enter a world of digital art without barriers.
SketchUp - 3D for Everyone
ZBrush - ZBrush is a digital sculpting and painting software solution.
AC3D - AC3D is a 3D software for games, virtual reality and flight simulation, scientific, medical and general data visualisation, rapid prototypes of 3D designs, 3D printing, Google Earth, X-Plane, Second Life and more.
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.