The Legend of Zelda: Breath of the Wild (NS) is the most successful stand alone Zelda title (not counting remasters/other versions)

[Medisti]

12.81m, according to here. Maybe it's over 13m since 3DS does have digital. Still, I don't doubt Breath of the Wild will manage to pass it given its momentum up to this point. It's still regularly in the Top 10 and... has it ever fallen out of the Top 20?