Even though I write it in 99% of my deviation descriptions, about three times a week I get comments, notes or emails asking what tools I use to create my work. Maybe this will help, but if people aren't reading the descriptions, it's difficult to believe they'll read this either. I hope this answers your questions as it's pretty detailed.
For Most 3D modelling:
I use 3D Studio MAX from Autodesk. - http://www.autodesk.com/products/autodesk-3ds-max/overview I've been using 3D Studio since rel.2 running on DOS. long before it was "Maxxed". It's my go-to 3D application for modelling and rendering.
For complex, detailed and accurate mechanical modelling:
I'll use (usually in combination) AutoCad and Inventor from Autodesk. http://www.autodesk.com/products/autodesk-autocad/overview and http://www.autodesk.com/products/autodesk-inventor-family/overview, AutoCad is a great layout tool and you can do 3D solid modeling in it as well. I'll often do my layouts in Acad then bring