Best "second party" Nintendo game

[Leynos]

Wman1996 said:

Second-party is confusing because it's not as mentioned as first and third.
If Mother 2 or 3, or Xenoblade Chronicles 3 count then I would pick any of those.

Monolith is wholly owned by Nintendo. Monolith is as much a 1st party developer as Naughty Dog is for Sony.  They also assist on Mario Kart/Splatoon/Zelda