MakeHuman

MakeHuman ( http://www.makehuman.org ) is a free and open-source tool for generating humanoid characters with detailed adjustments of proportions and other body/facial features.

HERE is a good example of how MakeHuman can be used to generate a medium-poly character well-suited for renders or game use - "Project Maiko" (!) by Colin Barton. The full list of updates/tutorials under the "Maiko" project is HERE

A recently developed alternative to MakeHuman is Manuel Bastioni Lab (developed by Manuel Bastioni, a former user of MakeHuman). Unlike MakeHuman, MLB exists only as a Blender plugin. It features new base mesh topologies, as well as a muscle rig for more advanced deformations. Facial animation and "proxies" (alternative topologies) are currently in development.

Another good alternative is Fuse.