Usually multi-carts are just loaded with tons of unofficial copies of officially licensed games, but sometimes you also find original games on them. Now sometimes these "original" games are really just ROM hacks, but sometimes they are actual, honest-to-goodness original games (even if they are a knock-off of, say, Angry Birds).
What are some of the best unlicensed games you've played on clones or multicarts? "Gems of the Orient" as you might call them.