madCAM: Funny name, awesome product
I am a Mechanical Engineer, so have extensive CAD experience but have never used a CAM program before. madCAM is my first. I did demo about 10 different programs before choosing, and madCAM had the best combination of ease-of-use, powerful features, and reasonable price. Knowing Rhino3D (since it only runs as a plug-in) is a big help but not required.