Blender - Blender is the open source, cross platform suite of tools for 3D creation.
CGTrader - CGTrader is an online marketplace at which artists can sell and buy Revit and 3D models.
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.
3DOcean - 3D Models & Accessories From $1 for 3D Models, Textures, Materials & Shaders, 2D Concepts...
Autodesk Maya - Maya is 3D computer animation software with powerful modeling, rendering, simulation, texturing, and animation tools for artists, modelers, and animators.
TurboSquid - TurboSquid offers 3D models for professionals.