Fusion 360

Fusion 360 is a professional level CAD/CAM program with many, many add-ons. Out of the options listed here it is the most robust. You can use Fusion online or as a program.

You need to sign up for an education account HERE

Fusion also has great resources for learning how to use it found HERE

Advantages

Professional level CAD program

Opens up lots of possibilities

Able to export not only STL, DXF, SVG, but also CNC tool paths and G-Code (Computer Version only)

Able to intergrate 3D models from vendors

Disadvantages

Requires a Computer for best results

Can get confusing or frustrating