Blender - Blender is the open source, cross platform suite of tools for 3D creation.
SelfCAD - SelfCAD is an online 3D modeling and slicing software.
ZBrush - ZBrush is a digital sculpting and painting software solution.
SketchUp - 3D for Everyone
DAZ 3D - Daz 3D, 3D Models, 3D Animation, 3D Software
open3mod - A free, Open-Source 3D Viewer designed to make it all easier. Massive 3D Format support