Than there’s Joël Robuchon's Pommes Purée. At least a couple of celebrity chefs have said they routinely hit certain restaurants that make Robuchon potatoes for the potatoes.
(Considering they’re about 1/3 butter, I’m not surprised.)
I’ve not knowingly had the opportunity myself. But there’s a place near me that makes mashed potatoes so good that when the chef stopped by my table to ask me how I was enjoying my meal, I complimented him on my food in general, but called out his mashed potatoes in particular. And he just grinned ear to ear. They may have been based on this recipe.