Some potatoes are definitely better for mashing. Higher starch potatoes like Russet or Yukon gold are best. Red potatoes also work. This recipe uses Yukon gold because they make a really creamy dish and have a naturally buttery flavor. I leave the skin on for this recipe because Yukon golds have really thin skins. The skins add a nice texture to an otherwise very creamy dish. You can remove the skins if you prefer.