pixeldudesmaker - Simple, web-based pixel art character generator.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Universal LPC Spritesheet Character Generator - Powerful, animated character generator for creating 2D spritesheets
RPG Character Builder - Create thousands of unique character sprites for your 2D game project - free!
ShapeShop - ShapeShop is an advanced and professional 3D design and modeling application that comes with an easy-to-use and user-friendly interface.
Misfit Model 3D - Misfit Model 3D is a 3D model editor that basically operates with triangle-based models.