Hi,

There a a lot of 3D Modelling software for Mac, each of them has it's own unique features:

https://en.wikipedia.org/wiki/Comparison_of_3D_computer_graphics_software

I'm having Rhinoceros 3D and Cheetah3D aboard.

Rhino was released recently and although the application does not have all the features available in the PC version, it has friendly interface and AutoCAD like workflow. Plus it could read and write DWG format directly.

I know that a lot of Mac users prefer SketchUp, but never tried it.

Maya and Cinema 3D are a good choice for animation.

Maxim