For me, the best Naruto movie is "The Last", it explained the most important thing that ignored in the manga and anime: when Naruto learn the true feeling with Hinata? And after this movie, the center of the whole store transfer into the next gerneration.
Also, a good movie must have a qualified villain, Toneri Otsutsuki. And I believe this is the first living Otsutsuki introduced after the 4th Shinobi war. It told us that the crisis not over yet, there are some more Otsutsuki live in the "universe". We made the Toneri Otsutsuki costume too and meet someone who also like this character, let see how it looks:
The costume is custom made based on her measurements and fits pretty good, if you like this one too, then here it is: