Actually, D&D took the step of referencing video games years ago. 3E's Tome of Battle, in its list of inspiration, mentioned the Soul Calibur games, among others. And that is certainly an interesting (and solid) choice for a game to illustrate the concept of fancy martial combat techniques for D&D. Anyone who has played a fighting game can rather quickly grasp the idea of combat more sophisticated than "I attack".
My personal "appendix N" would certainly include a few videogames. Tactics Ogre, Vagrant Story, Breath of Fire: Dragon Quarter, Demon's Souls, Romancing SaGa, SaGa Frontier, Final Fantasy 4, 5, or 6, Dragon Quest 5, 8, or 9, the The Legend of Zelda series, the Ys series, the Suikoden series (except 4), Etrian Odyssey, the Wizardry series for that matter, and so on.
Anime and manga also works as good inspiration. Berserk is good inspiration for anything really dark in tone. Studio Ghibli movies are good for many things lighter in tone. Naruto is quite good for any number of reasons (good portrayal of motivated heroes and combat involving teamwork, for example).
All I would hope is that any future appendix N doesn't stick to the same list that Gygax created years before I was ever born. That would be an incredible waste, since there are so many great sources of fantasy inspiration that have come along since then.