The always correct answer is to use whichever software works best for you.
Of course, that means that I'd use DoGA CGA L3 for making movies.
Seriously, if you made your models in GMAX, you'll need to find an external solution for your CG needs. What kind of animation do you need to do? trueSpace is a handy, once you get past the user interface. The same can be said for Blender. I'd suggest DoGA, but importing models is rather tricky. However, it does have some nice cel shading materials and a reasonable price, if that is your thing. [While DoGA CGA is free to download and great for game modelling, you'd need to register it to make movies or sequential stills.]
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TAZ
For future reference, I've used Anim8tor, trueSpace, POV Ray, Animation Master, DoGA CGA, Blender, and a horde of other programs for modelling, graphics, and animation.