Local multiplayer.
That is, I want my "peripheral" to be the capacity for the game to support a second controller and another human in the same room, not just over the rent-seeking network service.
I used to have to mess with these things:
Now it's easy, you can just have 4 controllers wirelessly connected to the console, no problem, but most new games don't have a splitscreen mode. Personally I've gotten to the point where I often won't buy a game if it only has online multiplayer.
Also, I want LAN parties back.
Online services have taken so much away from us.