%% This list of examples has been alphabetized. Please add your example in the proper place. Thanks!
* ''WesternAnimation/AdventuresOfTheGalaxyRangers'' was a very off beat show when it first appeared in 1986 with its blend of space opera, western and samurai motifs and an atmosphere that felt closer to a show from the early '90s rather than the mid '80s, what with all the NightmareFuel. Today it probably wouldn't look nearly as unique to a more cynical and less sensitive audience.
* ''WesternAnimation/BeavisAndButtHead'' debuted in the very early nineties, at a time when the AnimationAgeGhetto was still very strong, and ''WesternAnimation/TheSimpsons'' was just breaking through, while still remaining relatively family friendly. ''Beavis and Butt-Head'' on the other hand was shocking and caused a panic among the MoralGuardians, being one of only a very ''very'' few animated programs that didn't target children. Nowadays we have ''WesternAnimation/FamilyGuy'', ''WesternAnimation/SouthPark'', the entire Creator/AdultSwim lineup, and countless other "Late Night Cartoons", to the point that ''Beavis and Butt-Head'' looks tame, and downright corny by comparison.
** On top of that, the main reason it got such a diehard fanbase was ''because'' of all the shock and panic it caused (a lot of it undeserved). Now, years removed from the hype, explaining to today's kids what's so great about it is flat-out ''impossible''. With that in mind, it isn't too much of a surprise that the 2011 revival only lasted one season.
** Let's face it: before ''B and B'', the "ignorant 14-year-old with no future" trope had virtually disappeared from popular fiction. Not only that, but this show was maybe the first on television to accurately portray the average 14-year-old's sex drive. Or the average 14-year-old ''boy's'' at any rate.
* When WesternAnimation/BugsBunny first said, "What's up, Doc?" in the 1940 short, ''WesternAnimation/AWildHare'', it was a shock in ways modern audiences simply can't imagine or appreciate. In 1940, audiences saw the hunter (Elmer Fudd, of course), heard the hunter say he was hunting [[ElmuhFuddSyndwome wabbits]] (er, rabbits), and then they saw the rabbit. 1940 audiences were expecting that rabbit to scream, run, pick a fight, play dead, ''anything'' except strike up a casual conversation with the guy trying to kill him. So, when Bugs did that, he brought the house down - a response that led to it becoming his CatchPhrase. Nowadays, not only does nobody find, "What's up, Doc?" funny, most people don't even realize it was ever supposed to be funny in the first place. It's just that thing Bugs always says in ''[[OnceAnEpisode every freakin' cartoon he's in]].''
** The trope is invoked in the latest incarnation of the franchise, WesternAnimation/TheLooneyTunesShow. Even Daffy Duck can't remember Bugs' catchphrase any more.
* ''WesternAnimation/CodenameKidsNextDoor'' and ''WesternAnimation/XiaolinShowdown'' were the first mainstream Western animated comedies to undergo CerebusSyndrome and heavily experiment with a mix of serialized storytelling alongside more episodic fare, predating shows like ''WesternAnimation/AdventureTime'' and ''WesternAnimation/GravityFalls'' by several years. Any new viewers going back to watch these early 2000s cartoons would have trouble understanding why these shows approach to worldbuilding, season-long story arcs, and regular use of ChekhovsGun was so special at the time. These days, such cartoons have become more common. Back then, they were the only ones doing it.
* ''WesternAnimation/{{Daria}}'' is the [[TropeMaker quintessential]] self-aware high school program that broke from all established conventions and deeply satirized American culture and the teenage world view, at a time "teen shows" were generally limited to [[HighSchoolRocks light and comedic]] fare like ''Series/SavedByTheBell'' and ''Series/WelcomeFreshmen''. The tropes and archetypes have shown up in just about everything aimed at or about teenagers since and both the light and comedic, and the dark and [[DeadpanSnarker snarky]] tropes have been deconstructed, exaggerated, played straight and pretty much run into the ground since the initial run of the show in the late 1990s. It's hard, if not impossible, for people to appreciate just how much this show impacted an entire generation.
* Disney animation from the 1930s and 1940s: Think of this: many animation techniques have all been pioneered and perfected by the Walt Disney Company: synchronizing animation with sound, color animation, animated features, making characters appear as if they are actual personalities, dramatic atmosphere, overcoming technical difficulties (streaming rivers, ocean water, rain, light effects, shadows, fire,...), detailed backgrounds, having large groups of characters appear in the same scene, avoiding continuity errors, storyboarding scenes,... And all of it was done ''by hand''! Yet nowadays most people take it all for granted, failing to see how groundbreaking all these innovations were at the time and still are.
** ''WesternAnimation/MickeyMouse'': The world's most iconic cartoon character of all time is still popular ever since his creation in 1928, yet most people wouldn't exactly call him their favorite Disney character at all. Ever since the second half of the 1930s Mickey changed into a bland character who is more an extra in his own films and lets Donald Duck or Goofy steal the show. Many people nowadays wonder how on Earth this character ever became such a universal success? In reality, much of the early 1930s Mickey cartoons and comic strips show Mickey engaging in heroic adventures and use his strength and wits to overcome problems and villains, which is far more entertaining than what he would eventually become. And Mickey's success effectively proved that animated cartoons could be an artform and business at the same time. [[FollowTheLeader Without that mouse most of today's cartoons wouldn't exist]].
** ''WesternAnimation/SteamboatWillie'': For a modern day viewer it is certainly not Mickey's best cartoon and one might wonder how on Earth this ever got such a popularity that it practically launched the Creator/WaltDisney Company into the empire it still is today? Even the novelty that it was the first cartoon with pitch perfect sound synchronization looks rather unimpressive today. For instance, there is no speech, only music and extremely primitive sound effects. But at the time there was literally nothing like it! (It helps that ''Steamboat Willie'' is still very funny more than 80 years later, if perhaps only on a CringeComedy level now.)
** ''Playful Pluto'': A 1934 Mickey Mouse cartoon which is famous for a scene where Pluto gets stuck on a piece of flypaper. At the time this moment was groundbreaking in terms of character animation, because for the first time a character seemed to be thinking for himself, making the suspension of disbelief completely disappear. People who look at this scene nowadays will probably not be that impressed by it.
** ''Disney/TheTortoiseAndTheHare'': The scenes where the hare runs at SuperSpeed were very impressive in 1935 and influenced many other cartoons that came afterwards, especially ''WesternAnimation/LooneyTunes''. Yet, nowadays it actually doesn't look that notably quick.
* ''WesternAnimation/DonkeyKongCountry'' was groundbreaking in one respect -- not for being among the first wave of 3D-animated show, but rather, it was the first full-length, regular CG TV series to be animated entirely using MotionCapture[[note]]''The Moxy Show'' was the first TV serioes to feature motion capture-based animation, but only during short interstial segments, and in a comparatively jerky and limited manner.[[/note]]. While now widely used in blockbuster films and video games, ''Donkey Kong Country'''s use of motion capture was unprecedented enough at the time that an Emmy nomination for the show was rejected on the ground motion capture could not be considered animation. Nodaway though, the show looks hardly impressive, and modern audiences are more likely to laugh at the animation's frequent glitches, stilted movement and goofy facial expressions.
* ''WesternAnimation/{{Doug}}'' premiered in 1991, long before most SliceOfLife animated series were created. Nowadays, everything in ''Doug'' looks rather cliche, though that's mainly due to the nature of the genre meaning that many shows of this type are stuck using similar plots.
* ''WesternAnimation/FelixTheCat'': Back in 1919 and the 1920s Felix was the first cartoon character to become universally popular. There were several reasons for this. It was much more smoothly animated and took actual advantage from the fact that is is a cartoon by having visual puns and physically impossible gags, something earlier cartoons didn't do. Nowadays, however, with the advantage of animation in the wake of Disney modern viewers can find the silent Felix cartoons quite underwhelming, as there are no other characters besides Felix and most of the action is not as ''wild'' or ''funny'' as modern cartoons.
* ''WesternAnimation/TheFlintstones'' has been hit pretty hard by this trope. Let alone being the first true animated sitcom, ''The Flintstones'' was the first animated program to feature a predominantly human cast and episodes spanning an entire 30 minutes. Up until that point, cartoons were usually brief seven or eight minute shorts featuring {{funny animal}}s (with a few exceptions, such as ''WesternAnimation/BettyBoop'', ''ComicStrip/{{Popeye}}'', and ''WesternAnimation/MrMagoo'') either played in theaters before a movie or pieced together for television broadcasts. Hard though it may be to believe, episodic cartoons in general (let alone shows like ''WesternAnimation/TheSimpsons'', ''WesternAnimation/SouthPark'' and ''WesternAnimation/FamilyGuy'') would have never existed if not for this classic series about a "modern stone age family." But to modern viewers ''The Flintstones'' looks more like your average corny 1960s TV sitcom, only with a lot of AnachronismStew, lame rock and stone puns and animals used as modern day appliances, not to mention the obvious laugh track.
* Creator/HannaBarbera and their creations, ''big time''. When they made it big in the late 50s and 60s, the idea of animation -- a painstaking, laborious form of entertainment -- being produced on a television schedule and budget was considered a hopeless task at best, but their cost-effective, widely-appealing shows became revolutionary for such. But with more sophisticated production and creator-driven content taking over in the late 80s and 90s, many in the modern age just can't grasp how Bill Hanna and Joe Barbera became such big names in the world of animation.
* The relative tameness of old cartoons is lovingly parodied on ''WesternAnimation/TheSimpsons'' with "That Happy Cat", an early Max Fleischer-style "Itchy and Scratchy" cartoon, in which all Scratchy does is walk along a street. Even the 1920s and 1930s, Mickey could be subject to this after the rise of ''WesternAnimation/LooneyTunes'' and ''WesternAnimation/TomAndJerry''. It was also parodied in ''WesternAnimation/{{Animaniacs}}'', in an OriginsEpisode, where the three protagonists' history was established. Supposedly, they were first inserted in a cartoon with a character named "Buddy" to liven it up, after the producer claimed Buddy was "a cure for insomnia" ([[AluminumChristmasTrees Buddy was, in fact, a real Warner Bros. character who was phased out because his cartoons were boring]]).
* ''WesternAnimation/MightyMouseTheNewAdventures'' suffers from this badly nowadays. It was a revolutionary show and concept for its day, and essentially served as a training ground for future animation pros today, and for bringing back cartoon animation in the vein of classic cartoons to the mainstream in TV. However, today, due to the success of all the shows created in it's wake, especially ''WesternAnimation/TheRenAndStimpyShow'''' most modern viewers might not find it revolutionary, not helped that the show had many production woes and animation and art mistakes (as attested by former staff, [[http://johnkstuff.blogspot.com/2008/09/wonky-2.html including]] Creator/JohnKricfalusi).
* ''WesternAnimation/MyLittlePonyTales'' had a considerable impact on the SliceOfLife genre. These days, however, the series appears to be cliched and rather dated, even more so ever since ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' premiered.
* ''WesternAnimation/ReBoot'' was the very first fully CGI television show that came out in the [[TheNineties early nineties]] and was a pretty big success at the time. In this day and age, shows with CGI are completely common, and most people would consider ''[=ReBoot=]'' pretty tame in terms of computer accomplishments, although it had a great story, wonderful characters, and is still hailed today as one of the best, if not the best, CGI show of all time, with its biggest competitor for the title being another Mainframe series: ''WesternAnimation/BeastWars''. One thing that didn't help was that a year after it premiered ''WesternAnimation/ToyStory'' came out, with a movie-level budget and production time frame. Thus many people were dismissing ''[=ReBoot=]'' as a cheap, inferior product as part of ToughActToFollow. It is admittedly a little clunky to watch because of some stilted animation but there is no denying the amazing story and visuals of episodes like "Talent Night" and "Painted Windows."
* ''WesternAnimation/TheRenAndStimpyShow''. Unprecedented and freakish when it debuted, it practically invented the "gross cartoon" paradigm. The gratuitous amounts of snot, ToiletHumor and FamilyUnfriendlyViolence were something completely new and unknown to the audience. Nowadays, Ren and Stimpy wouldn't shock or disgust many people ([[{{Squick}} unless we're talking about the "Adult Party" version]]), with many cartoons that use similar tropes. However, the DVD boxes still sport parental guidance labels on them, and Common Sense Media rates it as unsuitable for viewers [[WhatDoYouMeanItsForKids '''below 15''']]. Honestly, how many kids' cartoons these days show characters pulling out [[{{Squick}} their nerve endings with a pair of tweezers?]]
* ''WesternAnimation/RobotChicken'' is an interesting example in that it's become this trope due to an entirely different medium. When it debuted back in 2005, its unique style of rapid-fire, witty humor and clever parodies of beloved pop culture icons simply couldn't be found in any other stop-motion animated show. The closest it resembled are the cutaway gags in ''WesternAnimation/FamilyGuy'', which is an animated cartoon. To an extent, that's still true; to this day, nothing like it exists ''[[ExactWords on television]]''. However, it's spawned countless [[FollowTheLeader imitators]] on the Web, a good number of which manage to stand out even in comparison to the show they imitate (see ''[[WebAnimation/ASDFMovie asdfmovie]]'', ''WebAnimation/TheLazerCollection'', and ''WebAnimation/SonicShorts'' for a few examples), so for someone who started on one of those series and was then introduced to ''Robot Chicken'' later, it likely wouldn't come off as anything special.
* Even ''WesternAnimation/RockosModernLife'' may have suffered from this. Back when it first premiered, the GettingCrapPastTheRadar moments were ''extremely'' impressive, and shocked many people. Lots of kids' cartoons nowadays, however, do the same thing, and so ''Rocko'' may not seem that impressive to some people who are used to watching ''WesternAnimation/AdventureTime'' or ''WesternAnimation/RegularShow'', the latter of which got "pissed" past the radar.
* ''WesternAnimation/ScoobyDooWhereAreYou'' debuted in 1969 on CBS and became Saturday morning's number 2 show (''The Archie Comedy Hour'' was the top show). Upon its success, Saturday morning became littered with crime-fighting/mystery-solving teens with wise-cracking animal sidekicks, many (if not all) by Scooby's studio, Creator/HannaBarbera. (Curiously, one such show, ''The Hardy Boys'', which aired on ABC opposite Scooby-Doo, was by Filmation.)
* ''WesternAnimation/TheSimpsons''. The first two seasons [[EarlyInstallmentWeirdness look really awkward to anyone who was introduced to it at a later date]], but it's hard to overstate how revolutionary the show was at the time, and how quickly it became a phenomenon.
** ''The Simpsons'' as a whole is very much a case of this trope by this point. During the show's golden age of the early to mid 90's, the show was extremely original, and not only because it was an animated program intended for adults. Its particular style of satirical, subversive humor made it stand out not only as a television cartoon, but as a ''comedy''. To younger people who have spent their adolescent years watching shows like ''WesternAnimation/SouthPark'' and ''WesternAnimation/FamilyGuy'', whose brand of humor is very much derived from ''The Simpsons'', it is probably quite hard to appreciate just how groundbreaking the yellow skinned family and their show were back in their heyday.
** And how controversial it was back then. The first season seems pretty tame, yet there were groups devoted to banning this show and its merchandise. Bart in particular was seen as a very bad example to children as he is a mischievous troublemaker. Yet, compared to later more evil child cartoon characters like Cartman or Stewie nowadays he almost comes across as adorable. Bart's most devious behaviour in the earliest seasons was sawing off the head of a statue, which he immediately regretted.
*** ''WesternAnimation/SouthPark'' acknowledged this in the episode "Cartoon Wars Part II." Bart makes a surprise appearance midway through the episode, explaining to Cartman what a "bad kid" he is by mentioning the time he sawed the head off a statue. Cartman counters this by referencing the time he fed Scott Tenorman his own parents, and Bart walks away feeling horribly dwarfed.
** And don't forget the numerous film references in ''The Simpsons''. They started this trend in animation and back then when they did it was often surprising, not done that often before and very amusing. Soon Disney movies like ''Disney/{{Aladdin}}'', the Dreamworks films like ''Shrek'' and ''WesternAnimation/SharkTale'' and every adult animated series, from ''WesternAnimation/SouthPark'' to ''WesternAnimation/FamilyGuy'' have been including references to popular films ever since.
*** In fact, ''WesternAnimation/FamilyGuy'' itself with its cutaway gags with references to popular films - even avoiding SmallReferencePools (not afraid to reference sometimes obscure authors or films) was one reason the show actually got noticed in the day. Nowadays, it's seen as "stale".
** Itchy and Scratchy's violent cartoons were originally intended as a parody of traditional cartoon violence like in ''WesternAnimation/TomAndJerry'' and ''WesternAnimation/LooneyTunes'', which was often very painful, but never bloody or fatal. So Itchy & Scratchy's gruesome battles surprised and shocked viewers because you never saw violence this extreme in mainstream animation. Nowadays, thanks to controversial and often gory shows like ''WesternAnimation/SouthPark'', ''WesternAnimation/FamilyGuy'', and ''WebAnimation/HappyTreeFriends'', the violence in Itchy and Scratchy doesn't seem that noticeable. Also, the disappearance of all classic 1930s-1950s cartoons on television means that the original reference target and thus the joke is lost on very younger generations.
** The concept of the trope itself is brought up in the first "Treehouse of Horror" episode. Lisa reads Creator/EdgarAllanPoe's ''Literature/TheRaven'' to Bart as an example of a truly scary story. Bart is naturally unimpressed and wonders why anyone would find a poem scary. Lisa theorizes that people in the mid-19th century were just easier to scare, having not seen any of the modern day's gore-fests.
-->'''Bart:''' Oh yeah! It's like watching ''[[Film/FridayThe13th1980 Friday the 13th: Part 1]]''. Pretty tame by today's standards.
** ''The Simpsons'' wasn't only revolutionary by the standards of animation, it was revolutionary as a SitCom and for comedy programs in general. As just one example, being animated meant ''The Simpsons'' weren't restricted to sets and {{Studio Audience}}s and gave them the freedom to introduce huge numbers of characters, not limited by actors and budget. It may not seem like much, but audience expectations changed as a result. If it weren't for ''The Simpsons'', we probably wouldn't have things like ''Series/ArrestedDevelopment'', or, if we did, they would look very different.
** ''The Simpsons'' also paved the way for continuity in an animated series. The episode "A Milhouse Divided" was subversive in that not only did Milhouse's parents, who got divorced mid-episode, ''not'' get back together by the end of the episode, later episodes depicted them living apart. (In fact even before this, Lisa's conversion to vegetarianism was a notable permanent character change.) Before then, all animated series, and most live-action sitcoms, had no continuity and relied on the SnapBack if an episode didn't end the way it started. This was even brought up in the DVD commentary. Nowadays, many popular cartoons have strong continuity; its sister series, ''WesternAnimation/{{Futurama}}'', so much so that ''The Simpsons'' is often labeled with StatusQuoIsGod, even right here on, as its own continuity is mild by comparison.
** Creator/MattGroening wanted ''The Simpsons'' to have a unique feel compared to the cartoons around the time (namely Disney and Creator/HannaBarbera). So he decided that the show was to have cartoon characters obeying real life physics (meaning: no squash and plump, no wacky sounds while characters do things or exaggerated facial expressions). Nowadays, most cartoons with an all-human cast are similarly restrained. Indeed, these days it would be considered strange to see "rubbery" humanoid characters in most cartoons, even most children's cartoons.
** ''The Simpsons'' is also often acknowledged as having been a GenreKiller for the entire genre of "functional family sitcom", a genre that completely dominated the airwaves in the late 80s and early 90s, and that many early episodes directly satirized. Homer in particular was a satire of the StandardFiftiesFather, an archetype that was still going strong, and, along with [[Series/MarriedWithChildren Al Bundy,]] he basically dunked it straight in the DeadHorseTrope pile overnight. Nowadays, family sitcoms are nowhere near as overwhelming, and wholly unironic family sitcoms are borderline nonexistent; it's expected that they be at least a little dysfunctional or cynical. Homer's own archetype, the BumblingDad, has gone from a sudden and surprising attack on the role of the father and American values to ''the'' standard sitcom protagonist, and often knocked for its frequently irritating nature and occasional UnfortunateImplications.
* ''WesternAnimation/SouthPark'' can apply this trope to itself. The DenserAndWackier early seasons seem shallow and unsatisfying compared to the [[ArtEvolution slicker]], more robust, [[CerebusSyndrome dramatic]] and sophisticated episodes that followed, but back when it debuted its unique brand of surrealism, [[ComedicSociopathy sociopathic]] satire and "less is more" animation were quite captivating to witness.
** Also, many of the jokes and issues that seemed downright shocking in the first couple of seasons now seem pretty tame and commonplace. A perfect example of this is the season one episode "Big Gay Al's Big Gay Boat Ride." Today, the episode's premise (Stan's dog being gay and Stan needing to accept it) seems like pretty standard TV-14+ cartoon fare. However, in 1997, this was about as edgy and socially conscious as cartoon plots got.
** And back then, practically every episode was considered "the most obscene thing on television", earning the series the wrath of many a MoralGuardian. Nowadays, the show is mostly left alone by MoralGuardians (in an ironic twist, even some conservative Christian leaders admit to being fans!) and only makes the headlines over a depiction of something offensive to a specific minority (ex. "Trapped in the Closet" and "200/201").
** A good example of the show invoking this onto itself is with the character of Eric Cartman. In the first four seasons, he was easily the most manipulative and foul-mouthed of the main characters but still a relatively harmless BrattyHalfPint. Even having moments of genuine concern and/or empathy from time to time (such as in "Cartman's Mom Is A Dirty Slut"). Compared to the conniving sociopath he would become in Season 5 ("Scott Tenorman Must Die" being the big turning point for his character), the Cartman of the first few seasons seems almost ''adorable'' now.
** An in-universe example occurs in "The Tale of Scrotie [=McBoogerballs=]". The boys are assigned to read ''Literature/TheCatcherInTheRye'', and are excited because of the controversy it caused... but become disappointed with it and write the eponymous book as what they think is controversial in response.
* ''WesternAnimation/SpaceGhostCoastToCoast'' pioneered the style of later Creator/AdultSwim cartoons: low budget; extreme LimitedAnimation with only stock poses and animations for characters; silly, borderline nonsensical conversations; and a dash of random humor (added in increasingly large doses as the series progressed). Today it seems tame compared to later Adult Swim shows such as ''WesternAnimation/AquaTeenHungerForce''.
* Creator/TexAvery created many jokes and situations in animated cartoons that were once surprising and hilariously funny, but have been imitated and plagiarized so much by other cartoon studios that these jokes can make a modern audience yawn because they are so predictable and overdone. Examples are the EyePop, the OverlyLongTongue, [[ChaseScene endless chases]], characters using sticks of dynamite or [[AnvilOnHead dropping anvils on each other]], characters [[GravityIsAHarshMistress walking on thin air before realizing that there's nothing beneath them whereupon they fall down]], the PaintedTunnelRealTrain joke,...
* Back in TheFifties, the cartoons from [[Creator/ColumbiaCartoons the UPA cartoon studio]] (especially Mister Magoo) were actually regarded as being very cutting-edge by having extremely sophisticated plots and animation at the time (to the point that a Magoo [=HiFi=] album was released in 1957). But nowdays, these storylines are the norm, as well as their then-groundbreaking [[ThickLineAnimation stylized animation]].