I use XYplorer on Windows. It is heavily customizable, which has allowed me to turn it into the File Manager I always wanted. The free version has everything I need, the pro version adds some features like scriptability.

On Android, I am using X-plore (free again), which is also very innovative (it takes a bit to understand its design philosophy), customizable again, and very good. Only issue I see with it is that whenever it is running, battery drain is measurably higher. Thankfully it has an exit button in the GUI.