One thing that I want to play with given a VM based windows installation is Win10 Lite. There are scripts available that strip out all of the uneeded crap in windows. I wouldn't run that on a live machine, but it might be fun to see just how lite I can get Win10 to go in a VM
I've heard there are versions you can download that have all the privacy stuff stripped out, but I'm wary of stuff like that being the paranoid InfoSec guy that I am...