The NES had an expansion port on the bottom.
The SNES also had an expansion port.
The virtual boy......existed.
The N64 had an expansion port, a ram upgrade, and a controller memory pack.
The gamecube had an expansion port, and a handle.
The Wiimote has a speaker inside, that only 1 game ever used (that I played).
The WiiU had the WiiU gamepad.
The Switch had the IR sensor, and HD rumble.