IMHO, XSI is the best of the bunch, but it's got the associated price tag, Maya Vs Max Vs Lightwave really is into the personal choice thing, I've tried all three and Max is my preference (given I can't get my company to cough for XSI). The other consideration is cinema, it's significantly cheaper then the others but still offers pro level features and is used at a pro level in some animation shops. The other question is what do you want to do? Games, Films, Adverts? then pick the packages best suited, Max is predominant in the Games world and also popular for TV, Maya and XSI probably have an edge in the film world.

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Toolset: Blender, GIMP, Indigo Render, LuxRender, TopMod, Knotplot, Ivy Gen, Plant Studio.