These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Adaptation Displacement: When Disney adapts a story or fairy tale, their version tends to become the best known and may influence future adaptations. The most remarkable examples are the fairy tale films from the Renaissance era, such as Beauty and the Beast and Aladdin. The stories were already Adaptation Overdosed and the Disney versions are only about 20 years old, yet they still manage to be the best-known versions. Averted in some cases, mainly when the Disney version flops. When most people think of Robin Hood, they don't picture him as a fox. Tarzan, though much better received, is also an exception because people are just as likely to picture Tarzan in live-action thanks to the many older films.
There are 54 films in the canon. It takes a full day to watch all 19 of the Walt-era films alone (Snow White to Jungle Book) and 73 hours and 59 minutes, or more than three days without sleep, to watch all 54 consecutively. Add on other Disney films which partially feature their animation, such as The Reluctant Dragon, Song of the South and the Pixar films, and you'll take even longer. Good luck.
For the things that spun-off from the Disney movies: there were 28 sequels made to the films that aren't part of the canon, not counting the Winnie-the-Pooh and Disney Fairies movies. There were also 13 spin-off series, including TaleSpin and Stitch!, totaling 775 episodes. As big as the canon is, if you really want to be through, you'll be at it for awhile longer.
Broken Base: You'll find fans who only love the Walt-era films, fans who love the Renaissance era films and view most of the older ones as Narmy, and even fans who love the earlier Renaissance films but don't care much for the later half. And then, of course, you have fans who judge each film based on its own merits.
There is a general consensus that, by the time Wreck-It Ralph was released, Disney had entered a new period of glory. The contention lies in exactly which film started this new period of glory, due to differing opinions over the importance of quality, financial success, and style:
Bolt, the first film made fully under John Lasseter, and received a respectably positive reception from critics, fans, and the box office;
The Princess and the Frog, which attempted to restore hand-drawn animation and revived many of the classic elements of Renaissance-era Disney; however, it failed to make a substantial profit, further damaging 2D animation prospects, and has had a mixed fan reception;
Tangled, which clearly established a new style for Disney, blending classic Disney traits with modern CG animation comparable to Pixar, resulting in the first CG film with a clear "Disney" look that would later be utilized in Frozen. Additionally, it was a major financial success for Disney, as well as a critical and fan hit.
Director Displacement: Expect only hardcore Animation buffs to know the names of the individual directors of the early Disney Films, everyone else giving Walt Disney sole credit. It didn't help matters that when much of the early Disney animated films were released, they were generally made by a team of segment directors under the command of a supervising director, who was himself answerable to Walt. Under that system, each segment director would direct a single portion of the film, and then report back to the supervising director so he could edit all the portions into a single, cohesive film.
Dork Age: Has gone through three distinct ones: the wartime period where they could only afford to make compilation films (of which only a few segments, such as Pecos Bill, Willie the Operatic Whale, Mickey and the Beanstalk and the entirety of The Adventures of Ichabod and Mr. Toad are well-remembered while the rest are usually forgotten); the period after Walt died and the entire company lost its way, in which production of films grinded to a halt; and the millennium years, where most of their films flopped. However, the only film anyone in the Broken Base agrees on as being undeniably bad is Chicken Little.
Strangely, in a recent book about the history of Disney animation, Hunchback was criticized and Hercules was outright panned by the author, who, apparently having no taste whatsover, went on to praise Chicken Little. While the rest of the book was well-written, this did not go unnoticed by snarky Disney fans.
Growing the Beard: Has happened three times over the course of the past 75+ years. The first was Cinderella, which was Disney Studios' first big hit since Dumbo. The second was The Little Mermaid, which was the starting point of the Disney Renaissance. The third and most recent was Meet the Robinsons, which was the first film released in the Lasseter Era.
Arguably, Snow White and the Seven Dwarfs is this for Disney as a whole, shifting away from the whimsical cartoons and into full length, and better animated stories.
Magnum Opus Dissonance: The Sword in the Stone has been criticized for being the most "through the motions" movie of Walt Disney's nineteen animated films, and admittedly the storyboard artists (and Walt himself) weren't that interested in the project from the onset. However the animators (especially Marc Davis) who worked on the film were incredibly proud of it, feeling that it had the most technically accomplished character animation of any of the films that they'd worked on.
Moral Event Horizon: Many of the movies have the main villain do some form of Moral Event Horizon at some point in the franchise where they wreak their havoc - mostly so that even small kids can tell who is the good guy and who is the bad guy, and determine that the bad guy DID deserve a violent death or, at the very least, a thoroughly spectacular form of Abject Humiliation Conga.
Seinfeld Is Unfunny: When it was released in 1937, Snow White and the Seven Dwarfs was genuinely considered by film critics to be one of the greatest movies ever made; in the decades since then though it's been parodied and copied to death. Watching it after years of being exposed to the media that it influenced (and was parodied by) is like watching cliché after cliché unfold predictably. Warning to parents: if you want your kids to love it, make sure they watch it early.
Strangled by the Red String: This is the case with earlier movies, particularly ones like Snow White, Sleeping Beauty and Cinderella. Justified, as it can be chalked up to Disney trying to keep to the source material, which in those cases were mostly fairy tales meant to teach morality and not build a believable love story. (The former two actually inserted scenes so that the "prince out of nowhere in the end" was actually introduced to both the audience and the princess earlier on in the movie, but they still get flak for it.) Later movies fix this, by giving the couples more interaction and personalities beyond "She's the girl of my dreams!"
Visual Effects of Awesome: This was the codifier (nay, maker) of sophisticated 2D animation as we know it, but the Golden Age films really stand out.
The Renaissance Age films were some of the first to prove the potential of CGI. As of late the animators seem to have created self imposed challenges to improve things considered difficult to make in CGI, such as hair (Tangled), snow and fabric (Frozen), and fire (Big Hero 6).
What Do You Mean, It's for Kids?: Most people think of violence as not kid-friendly, yet the vast majority of people (including Disney's marketing) consider these to be family or kids' films. Most of these films have a villain who tries to commit murder (and succeeds in the case of The Lion King) and ends up dead himself/herself by the end of the film.