CHIME NOISES INTENSIFY
I think I'd want to see N's childhood the most. As much fun as it would be to see Genesect destroy Team Plasma's lab, and to see Kyurem gobbling down people, I know how those would turn out. N's childhood... I don't really know how it would be! I know he lived in the castle, but I'd want to see Ghetsis introducing him to the injured pokes, how life in the castle goes about, how secluded he is etc. I could see it being really interesting. And after a little bit of his back story was revealed in BW2, I'd want them to delve into that more.
I think the least interesting one would be the one with the dragons. No offense, but it'd just be blah blah blah I hate you, my ideals rule and blah blah blah truth is where it's at, yo! I don't know, it' just strikes me as somewhat boring is all...
And I have NO CLUE how N's past would be summed up in five minutes because, A) it would be extensive and five minutes wouldn't do it justice and B) I don't know what exactly it would be about.