Blender - Blender is the open source, cross platform suite of tools for 3D creation.
pixeldudesmaker - Simple, web-based pixel art character generator.
ZBrush - ZBrush is a digital sculpting and painting software solution.
Universal LPC Spritesheet Character Generator - Powerful, animated character generator for creating 2D spritesheets
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.
meshmixer - meshmixer is an experimental 3D modeling tool for making 3D mashups without too much hassle.