The Rumble Pack for the Nintendo 64 was a first of its kind. Later controllers had a rumble feature built into the device, but the Nintendo 64 made use of its controller's accessory slot. The rumble pack was big, and even took batteries to use, but it was the first device of its kind for consoles.
Haptic feedback wouldn't be what it is today without the idea of a rumble feature immersing the player the way it did. Controllers used to be cold, non-living bits of plastic, and today they rumble and buzz at different frequencies and intensity to resemble what's happening on screen. Yet again, it's a small thing we don't think of today that was huge when they happened and very much changed how games are built.