Over the years, I have used an enormous number of CAD software packages. I think it would be difficult to overestimate the degree to which CAD has improved the design process!
Here is a list of all of the applications that I learned well and used regularly:
In addition to those listed above, I have also worked with these programs:
Solid Edge I think there was a free academic version of this available for a while.
RasMol and Yasara and several other molecular modelling programs (used mostly for research)
Materialise, Mimics: Generates CAD files from medical scan data. I'm sure this process is much less painful now than it was 15 years ago!
There was some other program in the 90s where the company dissolved, and the software became free. I can't recall the name, but I used it and followed its development for quite a while.