Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Pmx Editor - PMX Editor is for editing 3D model data to be used in MikuMiku Dance.
Xara 3D Maker - Xara 3D Maker transforms any kind of text, graphic or photo into a 3D logo automatically. You don't need any previous experience to produce professional results.
3DTin - 3DTin is a browser based 3D modelling tool.
K-3D - K-3D is free-as-in-freedom 3D modeling and animation software.
DeleD CE - DeleD is a 3D modeler and level-editor combined into one.