Console combo moments.

[luigiFTW]

On the gamecube it was possible to plug in a Game Boy Advance and play your gba games on a bigger screen. They also had some games with link functionality, such as playing as tingle in wind waker, minigames in sonic adventures and harry potter: the chamber of secrets, and full on link for multiplayer with a extra screen for each player in legend of zelda: four sword adventures and final fantasy: crystal chronicles.(though i never got enough gba systems with cords to try it out ;( ) when the wii came around the ds eventually gained one form of cross functionality which was demos in the nintendo channel. The original ds did not have access to a online shop of any kind, so to give demos to play you would connect to your wii and download demos from there. There was alot of fun games i would have never got to play otherwise, like rythm heaven, kirby mass attack, and a dragon ball game.
The dsi however, had its own shop, and another great title came out allowing cross functionality between wii and dsi. I was a wario ware game on dsi where you could make your own wario ware minigames! Later there was a wii game that allowed you to play these games you and others had made on the tv.
The most recent act of cross functionality is probably being able to use your 3ds as a controller in smash. Do you think nintendo should continue making things like this? I am almost positive i would have loved playing four swords adventures and crystal chronicles with my friends if i had the systems, and the 3ds is so popular now, a game like that on the switch may not be a terrible idea.

 

[Theresia]

This is a thing I personally like, it's fun to do cross systems activities, if obviously they're all side content not required for completion.
Sony, later, did with to a certain extend with PSP - PS2, like in Daxter where you get an additional skin from Combat Racing, and with Vita with limited remote play from PS3 and complete remote play with PS4.