If you were thinking “I should spend $130 on LEGO bricks and build a giant USB NES controller just to see what that would be like,” but you were afraid of spending that much money, [BrownDogGadgets] has you covered. He built a giant NES controller out of LEGO. The controller is designed in LEGO Digital Designer, which lets you create a virtual model, then get a full list of parts which can be ordered online.
The electronics are based on a Teensy LC programmed to appear as a USB keyboard, and the buttons are standard push buttons. The insides are wired together with nylon conductive tape. LEGO was an appropriate choice because the Teensy and switches are built on top of LEGO compatible PCBs, so components are just snapped in place. The system is called Crazy Circuits and is a pretty neat way to turn electronics into a universal and reusable system.
If that controller is too big, they’ve also used the same circuit with some laser cut parts for your own controller. If you do want to go even bigger, take a look at [Baron von Brunk’s] LEGO NES controller, which used the electronics from a real controller.