We use Rhino. A bit of a learning curve, but it has some great tools. I use it to develop curved surfaces, and unwrap them for art templating.
It plays nice with Illustrator, many cad programs don't. Great support...a TON of free plugins.
I had some 3d cad experience before I started using it, but there are a lot of tutorials included, and on the internet.
If you look at it...I'd hold off for Rhino 6...which is coming. Another bonus is they have a MAC version (although I prefer the
Windows version's interface.)
Also grasshopper is now included, and is extremely powerful. Parametric modeling is awesome!
Cheap compared to Autocad/Solidworks/etc.