Who was the best developer of the 6th Generation?

[Game_boy]

In Bold are the games that are either masterpieces or that somehow changed gaming. I've included the other because you did include a lot of mediocre titles too.

 

Fighting: Super Smash Bros. Melee

Racing: F-Zero GX, Mario Kart: DD, Kirby Air Ride, Wave Race: Blue Storm

Action-Adventure: Super Mario Sunshine, Luigi's Mansion, Legend of Zelda: Wind Waker, Legend of Zelda: Twilight Princess, Mario Vs. Donkey Kong, Pikmin, Pikmin 2, Metroid Fusion

RPG: Pokemon R/S/E, Pokemon Colosseum, Pokemon Colosseum XD: GoD, Paper Mario: TTYD, Mario and Luigi: Superstar Saga, Fire Emblem, Fire Emblem: PoR

FPS: Metroid Prime, Metroid Prime 2: Echoes

Strategy: Batallion Wars

Simulation: Animal Crossing


Sports: Mario Golf: TT, Mario Power Tennis, Mario Strikers

Rhythm: Donkey Konga
Party/Minigame: Mario Party 4, Mario Party 5, Mario Party 6,
WarioWare, Inc.: Mega Microgame$!
WarioWare, Inc.: Mega Party Game$

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So, Nintendo had matched quantity and I believe superior quality to Sega.