When i read the title GBA -> DS was the first thing that came to mind.
But I think GC -> Wii was better. The backwards compatibility was new for Nintendo in the home-console market and it was a lot less hassle compared to how WiiU handled Wii games. Each new home console before the Wii sold worse than its predecessor.
In the handheld market backwards compatibility was always there (up until Switch that is). 3DS played DS games, DS played GBA game, GBA played GBC games GBC played GB games.The transition is more blurry.