Inside Out has the usual excellent animation and enchanting humor and fun we've come to expect from Disney, but what's going to make this movie a huge hit, I do believe, is the message it conveys. I won't spoil it for you, but since you've probably seen trailers, you know it's about a young girl dealing with her emotions.
All through the movie, I tried to remember what is was like being 11. I won't tell you how many years ago that was, but it's been awhile. My honey and I discussed the movie and even though neither of us had the kind of upbringing Riley did, we could totally empathize with her plight. We all get Mad, Sad, Scared, and Disgusted, even when we try to keep Joy in the forefront. Riley feels all these sensations and attempts to sort them out. Sometimes one rules, sometimes another. How Riley works out her feeling and how all the emotions come to peace with each other is a great message for everyone, young or old.
You can read the full plot at Wikipedia, but I recommend seeing the movie first so you can be delightfully surprised.