Autodesk Maya Complete is an Academy Award winning 3D animation, modelling and rendering tool. The version listed on this site is version 7, but in my review I will concentrate on Maya in general since version 7 is a few years out of date - the current version is Maya 2009 (effectively corresponding to version 10).
I think of Maya as the old work-horse of 3D animation packages. It's a bit like a big old Clydesdale, which is strong, reliable and hardworking even if it can't always quite keep up with the pace of some the younger upstart ponies. New features are added with every release, although lately these have tended to be more or less limited to the addition of some off-the-shelf 3rd party plug-ins into the main programme, along with minor cosmetic changes to the user interface.
Maya is available for Windows, Linux, and Mac OS, so no matter which operating system you work with you should be able to use it. It is also now available in 32 bit and 64 bit editions - the 64 bit version produces better performance thanks to the greater available memory.
One of Maya's greatest strengths, and the thing that probably most sets it apart from other packages such as 3D Studio Max, is its open-endedness and degree of customisability. Thanks to its own scripting language, MEL, it can be tailored to suit virtually any production needs. In the hands of a talented developer, it can be customised with extra tools, features, and functionalities to ease even the most complex tasks. Newer versions (8.5 onwards) also support Python scripting, adding even greater customisation and pipeline-integration possibilities.
The animation tools in Maya are quite powerful, in particular the graph editor provides animators with a great deal of control over their work. There are both IK and FK settings in Maya's rigging tools, allowing for great control over a character's range of motion. Modellers may work with polygons, NURBS and Subdiv surfaces and the modelling tools are very intuitive. There is a hardware renderer, a software renderer and the mental ray plug-in, although I would have to say that rendering is one of Maya's weaker points, particularly the software renderer has some limitations. However there are so many plug-ins available, including RenderMan and MayaMan, that this is hardly an issue.
There are many dynamic effects in Maya including particle systems, and both rigid and soft body physics. Some of the more powerful effects tools, including nCloth, Fluid Effects, Fur, and Hair, are not available in the "Complete" version and only come as standard with the more expensive "Unlimited" version.
Maya is a really powerful production tool for 3D artists, which is in use in many FX and animation studios all over the world. It is extremely accesible and user friendly. I would recommend it for use in all your 3D animation, modelling, and rendering needs.