Blender - Blender is the open source, cross platform suite of tools for 3D creation.
TurboSquid - TurboSquid offers 3D models for professionals.
Autodesk 3DS Max - 3ds Max is software for 3D modeling, animation, rendering, and visualization. Create stunning game enrivonments, design visualizations, and virtual reality experiences.
STLFinder - The 3d models search engine.
ZBrush - ZBrush is a digital sculpting and painting software solution.
3DOcean - 3D Models & Accessories From $1 for 3D Models, Textures, Materials & Shaders, 2D Concepts...