Is it wrong that when I think about having a granddaughter, one of the first things I think about is the best tabletop roleplaying game to get a new young player started with?
Leaving aside my future granddaughter for the moment, I think the question itself is interesting. I expect that most folks from my generation of gaming got started with one of the early editions of D&D. Basic D&D has some advantages as a newbie RPG: the rules are fairly simple, and the random character creation aspects prevent you from having to know much about the game in order to create a character. However, it is a very combat-centered game, and some of the rules concepts (such as the to-hit table) have been replaced by much more straightforward mechanics in more modern RPG's.
Fate (my current favorite RPG) shifts the emphasis away from combat and toward storytelling. Plus, it's sufficiently generic that it can be used to tell a variety of stories other than the standard D&D "kick in the door, kill the monster, and take the treasure" story.
My gut feeling is that the narrative freedom of Fate is a bit much to throw at a new player, but this might just be a result of the fact that my first RPG experiences were of the D&D variety. The processes for rolling initiative, checking armor class, and marking off hit points and such are part of my roleplaying "muscle memory" at this point; they're instinctive. If my first game had been something like Fate, would I have learned it with the same ease (or difficulty) as when I learned D&D? Or is a "simulationist" game such as D&D inherently easier to learn than a "narrativist" game such as Fate?