What was the best Nintendo partner that went MIA?

By MIA (missing in action), either they disappeared from making games (Skip), ceased to exist, or stopped working with Nintendo on projects (Noise). These can also include big name publishers that directly worked on Nintendo IP for some time, before stopping (like Capcom with handheld Zelda titles in the early 2000's). With that in mind, here is a short list of some MIA Nintendo partners:

Treasure - Sin & Punishment, Wario World

Noise - Custom Robo

Skip - Chibi Robo

Red Entertainment - Fossil Fighters

Vanpool - Tingle, Dillions Wild Western

AlphaDream - Mario & Luigi

Monster Games - Excite Bots/Excite Truck/Excitebike, Wii ports to 3DS

iNis - Elite Beat Agents/Osu! Takakae! Ouendan

Tose - The Legendary Starfy