Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Sculptris - Sculptris: Enter a world of digital art without barriers.
MakeHuman - MakeHuman is a free, open source, interactive modeling tool for creating custom 3D human characters.
Misfit Model 3D - Misfit Model 3D is a 3D model editor that basically operates with triangle-based models.
Bforartists - Bforartists is a fork of Blender.
ShapeShop - ShapeShop is an advanced and professional 3D design and modeling application that comes with an easy-to-use and user-friendly interface.