This article has a talk page!Games for the Famicom and NES that were produced without the permission or knowledge of Nintendo.
When the Famicom first released in Japan, the system had no lock-out chip and despite efforts to control what third parties released in Japan, it resulted in an unhindered stream of unlicensed games from the mid-80s right up to the present day, both in cartridge form and (more recently) built into countless plug & play and handheld consoles that appropriated the system's hardware.
By the time Nintendo first released the NES in North America, it had a lock-out chip built in to prevent developers from creating games without Nintendo's permission. Not that this deterred some developers...