Blender - Blender is the open source, cross platform suite of tools for 3D creation.
FreeCAD - An open-source parametric 3D modeler
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.
Sculptris - Sculptris: Enter a world of digital art without barriers.
V-Ray - Learn why V-Ray for 3ds Max’s powerful CPU & GPU renderer is the industry standard for artists & designers in architecture, games, VFX, VR, and more.
meshmixer - meshmixer is an experimental 3D modeling tool for making 3D mashups without too much hassle.