Fandoms
Of all the production companies in the history of ever, Pixar may have the greatest track record of creating incredibly high-quality box office hits. As of 2016, they've made sixteen movies and only one (one!) isn't "Certified Fresh" on Rotten Tomatoes. (Sorry, Cars 2, you're just not up to par.)
So, it makes sense that Pixar also has a pretty devoted fan base. Pixar fans might love Toy Story—the movie that started it all—but how can they keep from adoring Finding Nemo, Up, and Inside Out too? It's tough to focus on one great computer-animated film when so many awesome ones are staring you right in the face.
You'll find Pixar fans compiling lists of hidden Easter eggs, geeking out over animators, and developing a theory for all how all the films in the Pixar universe are actually secretly intertwined.
Oh, and it's true. To geek out right along with them try visiting Pixar Planet or Pixar Times.