Feel free to add to this list by making a reply. As the list and discussion grows we will create a sticky or wiki page for it and post a link on the main page.
- SpaceClaim Engineer (excellent STL editor and CAD $$$)
- DesignSpark Mechanical (sponsored version of SpaceClaim FREE)
- Autodesk Fusion360 (online and very feature reach cad FREE to $$)
- DraftSight (2D drafting software by SolidWorks FREE)
- SolidWorks (3D cad pretty much a standard... $$$$)
- Sketchup Make and Pro (3D direct design cad FREE to $)