Female protagonists. I am not sure why precisely but I think having a female protagonist significantly boosts the rating of a film in my lists of favorites. This became clear when looking at the trailers for the Russian animated movie "Space Dogs" about the first animals (namely two dogs) to go into full space orbit and return alive. Wiki says "They were accompanied by a grey rabbit, 42 mice, 2 rats, flies and a number of plants and fungi. All passengers survived." I thought at first that the main characters were all male but one-by-one I realized the three main characters (dogs and a rat) were female and with each realization, I wanted to watch the film all the more. I made all sorts of excuses why I liked Secret of NIMH so much but upon rewatching, I realized those were not as strong as I made them out to be because other films had those elements and failed to interest me. I am concluding that having a female protagonist was a significant pull for me. I recently found a beautiful film only released in Korea (that may change soon) called "Leafie, a Hen Into the Wild" (2011). Like Secret of NIMH, most of the characters are male but the lead is a female and specifically a mother doing everything she can for a child of hers. The mother aspect might play a role too but looking at my favorites, just being female is a big part of it. I am obsessed with the unwatched Korean film "Outback" (may have other names like "Koala Kid"... not clear what they will call it in English) and I can assure you it is not the protagonist that interests me. The female co-star and the subject of the plot, her younger sister are significant draws along with the Tasmanian devil character (simply for being the first realistic cartoon character design of that species). I have seen a few all-female cast films and shows and they don't score higher so it is not numbers of females but simply that they are the main characters moving the plot along. "Lady and the Tramp" did not do it for me because Tramp made all the decisions. "Lilo and Stitch" had the pull of an alien character but more and more I am realizing that the two orphaned sisters trying to make it on their own is the real draw. "Home on the Range" did not fair well with audiences... likely due to the protagonist trio being cows. For me, three strong-willed and very different female characters making all the decisions keeps that film high on my favorites list. Note also that almost all the other characters are male with the exception of the lead human character, the old lady who owns the farm (a protagonist in a way too and at least the main feature of the object of the quest... to save the cows' farm).