I've thought about doing this many times in the past, just as a practice, but have never got round to it. The idea is to take an episode of your favourite TV show, and write it as a short story. Right now, an old episode of Only Fools and Horses is showing (it's a classic in England) and as always, I'm struck by the brilliance of the writing - some of the exchanges in this particular episode are so good, that the laughter track kind of spoils it, and I find myself imaging how good a social drama it could be without it. The story would be funny - because of the naturally funny dialogue in the episode - but it would be interesting to do this and see how it reads as a short story. It would also be good practice for my third-person writing.
If you say so In all honestly I have no idea what 'fanfiction' is. I've heard the term, but it's something my instinct tells me to avoid like the plague.
It would be like following in the footsteps of Alan Dean Foster, the king of movie novelizations. A very interesting idea, @OurJud.