If there's one thing TV executives like doing, it's replicating success, which is why spin-offs have been so popular. It's understandable why they are so prevalent; after all, if audiences love a show, it's reasonable to assume they'll give a similar one a look — especially if they have a character, brand name, or premise that's similar enough. Yet the best spin-offs are able to exist on their own, separately from their predecessors, distinguishing themselves as great TV shows in their own right.