There are 56 films. It takes a full day to watch all 19 of the Walt Disney-era films alone (Snow White to The Jungle Book) and 77½ hours, or more than three days without sleep, to watch all 56 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: First of all, there are those who like them as adults and liked them as kids, those who liked them as kids but not anymore, those who never liked them as kids but have since come to believe they have good quality, and those who have never liked them even as kids and dislike them with a strong passion.
You'll find fans who only love the Walt-era films, fans who love the xerox period (which goes from 101 Dalmatians to, approximately, The Great Mouse Detective — although many of those fans classify The Black Cauldron as being out of this period), 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, the characters in The Three Caballeros (and the film itself to some) 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.* Although, there are few who would classify this film to the point where it's So Bad, It's Good
Likewise, criticizing thebigfourfilms of Renaissance era Disney is a no-no among fans, since those are considered to be in the same league as the Walt-era Disney features, or at least great films in their own right. The later films from that period, such as Pocahontas, are divisive enough in reception to evade this, though.
In a bizarre case, the success of Frozen seems to have pushed Tangled into this status, as the FrozenHatedom rallied around the cause of promoting Tangled as a superior effort while, simultaneously, the FrozenFandomalso promoted Tangled as a film the fans should check out. In this way, the forces of Friendly Fandoms and Fandom Rivalry combined to retroactively make Tangled a Disney Sacred Cow.
Germans Love David Hasselhoff: A few Disney characters are surprisingly popular in another country. Sometimes even the film itself would turn out like this.
Stitch is huge in Japan with an anime and manga adaptation and there's tons of Stitch merchandise that can be found everywhere in Japan. The same goes for Angel who has a bigger role in the anime, and she's not even from the original film.
Marie is also huge in Japan to the point that she was given her own spinoff in March 2015 called "Miriya & Marie" and there's a lot of merchandise that feature her in Japan.
Ariel is also a very popular Disney princess in Japan due to the Japanese loving stories about mermaids.
In general, Disney animated movies tends to have their second or even highest gross in Japan, inspire many of its anime creators big name and even created the Kingdom Hearts franchise. This, couples with the unpopularity of every other American feature animation studio in the country (with the exception of Pixar, occasionally) reached the point where a lot of new releases aren't even sent to Japan, while others go straight-to-DVD.
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 short cartoons and into feature length, and better animated stories.
Harsher in Hindsight: Nine Old Men alumni Woolie Reithermann dying in a car crash only a few years after he retired became this when one of Disney/Pixar's elite animators, Joe Ranft, also died in a car crash 20 years later, and this fate nearly claimed Jeffrey Katzenberg's life too 10 years later, and 30 years after Reithermann's passing.
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 (excluding Bill Peet) weren't that interested in the project from the onset. However the animators 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 the small kids the films are targeted towards 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.
Never Live It Down: The 2004-2005 Dork Age, specifically the transition where Disney stopped doing traditional animated features in favor of CGI animated features. However, Disney got better once John Lasseter took over and the studio made hits afterwards.
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.
Sequelitis: While multiple films have received sequels, only a few are considered official.
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!"
The Renaissance Age of Animation films are 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), fire (Big Hero 6), fur (Zootopia), and water (Moana).