I can see how former Windows users might like Unity -- I hate the default configuration . Unity Tweak Tool can make Unity much more usable.
KDE and Kubuntu for the win if you are using newer hardware.
Xfce is 'old school' but LINUX gives you that option instead of Windows bloatware shoving pretty down your throat. That is what LINUX desktop is all about -- freedom and choice. Most software is open source and you can mess with its executable code were need be if you are able.
the GTK
https://www.gtk.org/ is very configurable so you can customize a lot of things user or system-wide.