NCIS: Los Angeles.

Television has an abundance of things, but great original ideas are not high among them. Many promising new series have set sail in TV's vast ocean, only to be dashed against the jagged rocks of audience indifference, sinking out of sight forever.

But just as sequels, prequels and reboots help Hollywood overcome its creative deficit in film, spin-offs can be a way of taking a known TV quantity and fashioning it into something new. Sometimes it works so well you get Inception-style layers of spin-offery, such as the military legal drama JAG producing the spin-off NCIS, which in turn was spun off into NCIS: Los Angeles.