What are the best potatoes for mashing into those golden, buttery piles of steamy starch — the ones that, when made properly, are equal parts rich and fluffy? Yukon Gold potatoes are the best for mashed potatoes. Yukon Gold potatoes have the densest and most uniform flesh of the potato varieties. When cooked, they aren’t grainy, watery, or mushy, which all happen to be qualities that ruin mashed potatoes instantly. And as an added bonus, Yukon Golds already have an inherent buttery flavor to them.