You want to use Russet Potatoes or even Yukon Golds. They are a higher starch potato and will yield the fluffiest, smoothest, and most flavor-packed mashed potato. You will want to stay away from waxy potatoes like a red or white potato. These require more mashing to become creamy, which could lead to the dreaded potato paste. Which is what I would almost always get every time I was trying to make mashed potatoes. I know it's crazy to think a food blogger having issues making mashed potatoes, but y'all... the struggle has been real!