For CAD and 3d design in general, I oreger Rhino. The grasshopper addition is phenominal,.and I've been using Rhino for almost.. 20 years now. I really enjoy the look and feel if it, I know basically every relevant command line input and input option etc. I use Revit and AutoCAD at work, but convinced them to get my Rhino for developing 3d models and converting them to 2D.

The only truly free program that competes with Rhino is Blender, which is an amazing program in a whole bunch of regards, but I've never liked the GUI at all.

Speaking of things Blender can also do, I prefer Photoshop to popular free alternatives such as GIMP or Blender. I'm very familiar with the tools and how they work, and the Beta improvements are mind boggling. I do however prefer Inkscape for vector work.

Speaking more about things Blender can also do, I prefer DaVinci Resolve as a free movie editor. However, I did purchase the basic license becuase I thought the program was that good. I'm blown away that they make it free with so many things enabled still.

Speaking ...Blender.. you get the idea.. digital sculpting is much nicer in Zbrush, to me. Took me forever to not hate the GUI (cough -- ok I still Hate it), but I really love some of the tools and plug-ins. It's also phenominal at mesh repair in general. Which is a subtasks I prefer Netfabb Basic for, which I think is also paid for now, but I think suspect it's included in my Autodesk license package..

The moral of the story is if you like to do any of these things go check out blender before you get used to a paid program, and save yourself decades of costs lol.