I'd like to have QGIS, an open source GIS with CAD capatilities
The most useful version is "current version" (long-term version is intended to be used in production environment, for personal use current version is better)
Download page (https://www.qgis.org/en/site/forusers/download.html)
Download link example for 64 bit (http://qgis.org/downloads/QGIS-OSGeo4W-3.6.3-1-Setup-x86_64.exe)