Now here's something I don't know a ton about. I know that there are TONS of pirate carts out there, especially for Famicom and Mega Drive, but I'm not really familiar with how prevalent they are, where they come from, and what other systems have pirates or unlicensed games.
To my knowledge, there are TONS of Famicom pirates, some inexpensive Mega Drive ones, and a few unlicensed PC Engine CD and huCard games (mostly hentai). There's also a burgeoning pirate market in South America via Tectoy and other manufacturers. What do you know about import pirate carts?