Depends on what method for modeling you use.
-If you use old mdethods :
Extrude, loop cut etc ... Silo, Modo, Blender and lot of programs are ok.
-If you sculpt than retopology to make the low model and normal maps : Zbrush , 3D Coat, Blender are the ones i've tried and are ok !
For Mudbox,Modo,etc ... i don't know for them in that parts.


There are generic character makers tools like poser, but i find them really generic in terms or results, depends on what design and game you target !

If you plan to make really personnal characters, humanoids , creatures or mechanical , the best modeler is YOU : ) !!