This is more complicated. Even within one brand top of the line power cord may not be best for every component and every type of the component.
But if I wanted to disregard what I just said myself I would first put 'the best' power cord on the regenerator. PS Audio regenerators greatly benefit from good cords, just like any other type of components, or more.
In my experience, tape decks of various kinds, including pro SVHS, are less demanding, but they benefit too.