+1 to Blender if you want to go with a free tool. Nothing at its price bracket can challenge it, and the other full 3D Packages are just prohitively expensive when they give you more or less the same that Blender does.
That being said, if you have a small budget to spend on tools, Maya Lite is now available, giving you the most important Maya tools for around 800$, or 30$ per month. I cannot really recommend it, hated the way it made Blenders obscure navigation look easy to me. If Blender now really support Vertex normals, I will cancel my sub.
What DOES get my full recommendation is 3D Coat. Gives you all you get with zBrush, with a more accessible UI and an extremly good retopo toolset, for half the price... around 350$ per license last time I checked. This is not a fully fledged 3D Package like Blender, but what it does (Sculpting (Voxel Sculpting), Retopo and UV remapping, 3D painting), it does really well, outdoing Blender at these things with ease.
ZBrush also isn't too expensive, altough we are now in the 700$ territory. If you don't know ZBrush, google it. The Industry standard for Sculpting.
If you want the best lowcost tool for NURBS Modelling and "CAD Lite", MoI is a great little tool that can be had for under 300$... for CAD like modelling it is REALLY quick and accessible, making hardsurface modelling of tricky models a breeze.
Then there have been a whole lot of additional tools that are cheap that might interest you:
- CrazyBump... if you don't know it, might want to have a look. Tool to generate different maps from different inputs. Really great to generate heightmaps from normals and the other way round. 100$ for a personal license
- Fuse... AFAIK the tool is free, but heavely integrated into the whole mixamo ecosystem. Though if you don't want to pay, you can use it without paying a cent. a "character creator", you can create your human or human-like character from parts and dress it or outfit it with accessories.
- Mixamo... can get expensive quickly, but single animations are not that expensive, and the autorigger does work quite well. If you have not too many characters that need to be animated and don't know how to animate it, or how to pay an animator to do it, maybe look into the Mixamo service... you can get your character rigged and buy animations (down for the time being as Adobe bought Mixamo... I REALLY hope that doesn't mean crappy integration into Adobes Creative Cloud in the future).
But really, start with Blender. It might not do everything as well as some of these specialist tools, but at 0$ cost, nobody can complain, especially when it still does things not to bad. And it really does all, from Boxmodelling to Sculpting, Retopo, Rigging and Animations, to NURBS modelling.
I just wanted to chime in since Gian-Reto mentioned our stuff-n-thangs but the information was a little out dated. Adobe has made Mixamo free for a limited time, so you can get unlimited characters and animations with just an Adobe ID. Includes the following:
