Microsoft PowerToys is a fantastic program if you like to tweak your experience with Windows.
It lets you do things like set up individual zones within your monitor that act like picture in picture or another monitor. It has a robust color picker, which helps greatly when it comes to photoshop and template creation. I also use the text extractor very often to extract text from pictures, which it copies to the clipboard.
The best, and technically the worst, is it lets you change settings that you can't normally do in Windows.
While it could get someone YOLO adminning in trouble, thankfully it has a lot of warnings before you mess things up too badly.
Those are the features I use, but there are too many useful features to name in one go.