Serious moviemakers, animators, and graphic designers are a demanding bunch. For them, using the best tool for the job is more important than a low (or at least affordable) price. Blender is one major exception to this rule.
An open source project, this modeling and animation program competes with much more expensive commercial products such as Autodesk Maya. Yet, unlike other free and low-cost alternatives, Blender ran fast, never crashed, and offers a wealth of deep features.
Unless you are a 3D modelling expert already, it might take some time to learn how to use Blender. Over several days, we built several models with basic polygons, textures and intersecting curves. Even then, our creations were a far cry from what a true artist and modeler could do with Blender, judging from the YouTube videos and tutorials that show the power of this modelling app.
The interface looks a bit daunting, and runs in a virtual environment (so it does not follow any Mac conventions for menus or dialog boxes), but is actually fairly straightforward. You can press spacebar to add an element or apply an effect. Shortcut keys (like S to size and R to rotate) make it easy to adjust objects. Blender also makes it easy to render your image with texturing and lighting. Windows can be layered and arranged in countless way to match the workspace you prefer.
The app supports Python scripts (a programming language), rigging (a process of using wireframes to build the underlying shape, such as the skeleton bones), an animation engine (for creating complex sequences that mimic the movement of real world objects, shading (for adding texture and reflections), compositing (building individual components of an animation or model) and even an engine for creating scientific particles that you can render into a complex geometric shape.
Blender even supports "soft body" animations, such as a blanket that falls over a ball in a realistic way.
Really, this tool has an endless array of advanced features that will meet the needs of demanding animators and 3D artists, and is also a great entry point for those who want to try the craft.