Engineering

3DS Solidworks (for simple models; better for surface modelling)
Autodesk Inventor (flexible)
Autodesk Revit (better than AutoCAD nowadays)
3DS CATIA V5/V5-6/V6/3DEXPERIENCE (for complex; better for solid modelling)
Autodesk Fusion360 (beginner; student edition)
PTC Creo Parametric (formerly Pro/E Wildfire)
Rhino 3D (someone said it was very easy; Parametric design)
OpenSCAD (coding CAD)
Siemens NX

Notes

• See Creo Parametric vs Creo Direct

One is like CATIA V5-6/SolidWorks, where everything is relational. The other is like CATIA V4 where things stay where you create them. At times, making a robust model in Creo Parametric is more like programming than drafting.

• Understand Scale and Machinability