What's you preferred potato cut shape? Round? Rectangular? Hash browns?
Definitely hashbrowns and their equivalent. They're the sausage of the potato world.
Commercially, potato cakes at Arby's, hashbrowns at McDonald's, tater tots (with chili and cheese please!) at Sonic, the tater rounds on the breakfast menus at Chick-fil-A and Burger King...
At home, a box grater and cast iron griddle.
Protip: shred them the night before and soak them in ice water over night in the fridge. That way you can shave quite a bit of time off your cooking in the morning. Use a potato ricer to squeeze out all the liquid.