Blender - Blender is the open source, cross platform suite of tools for 3D creation.
TurboSquid - TurboSquid offers 3D models for professionals.
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.
STLFinder - The 3d models search engine.
Autodesk 3DS Max - 3ds Max is software for 3D modeling, animation, rendering, and visualization. Create stunning game enrivonments, design visualizations, and virtual reality experiences.
3DOcean - 3D Models & Accessories From $1 for 3D Models, Textures, Materials & Shaders, 2D Concepts...