Blender - Blender is the open source, cross platform suite of tools for 3D creation.
SelfCAD - SelfCAD is an online 3D modeling and slicing software.
FreeCAD - An open-source parametric 3D modeler
SketchUp - 3D for Everyone
meshmixer - meshmixer is an experimental 3D modeling tool for making 3D mashups without too much hassle.
Autodesk 3DS Max - 3ds Max is software for 3D modeling, animation, rendering, and visualization. Create stunning game enrivonments, design visualizations, and virtual reality experiences.