There are a number of tests that determine the degree of your NES mastery, such as beating Contra without using the Konami code, or speed running Super Mario Bros. without using any power-ups. Alternatively, you can beat Super Mario Bros. by using your coffee table as a controller: that'll take some real skill.
Thanks to furniture maker Charles Lushear it's now possible to do just that, as he's designed a wooden coffee table that's also a functioning NES controller. It has a detachable glass cover for when you're actually using it as a table, but will plug into an NES like a standard controller, with the image below bringing a new definition to co-op play.
At $3500 and with a 4-6 week waiting time, this isn't a piece of furniture that you can pick up at your local store. Still, if you want a new way to play the good old NES, here it is.