Kim Possible has several Game Boy Advance games. The second and third ones especially put a lot of effort into getting all the little details right; from the ridiculous Drakken plot to Ron dancing like the Oh Boyz, they nailed the look and feel of the episodes.
Transformers Animated has won over many of its detractors not only with a well-written plot and episodes, but also through lots of shout outs, small and large, That show that the writing and animation teams do in fact know and care a lot about the series' that came before.
Freakazoid!'s "villain" Fanboy once drove the eponymous hero nuts with gobs of detailed information about Disney movies.
While Godzilla: The Series had Artistic License in force for obvious reasons, most of the material seen and talked about had basis in the sciences at the time of the show's airing. Even a few non-science subjects are presented accurately, such as Mendel Craven using his sock to filter water for drinking purposes in one episode, a real life wilderness survival technique. In fact, this show is actually much more scientifically accurate than the film that preceded it.
In Turtles Forever, several details about the continuities are thrown in. Such as the fact that Mirage Leonardo's dialogue is peppered with actual dialog used in the first issue. There are a few other noteworthy examples, such as that thing that sniffed out the Turtles lair actually is from the old show, most of the other continuities also get a Shout-Out, in the form of a hologram made by the Technodrome, showing almost every continuity, (yes, even the OVA's) with notable omissions being Ninja Turtles: The Next Mutation due to Laird's issues with it and the various video games, as well as that, Tokka and Rahzar also make an appearance for a few seconds. While the 1987 Turtles personalities were exaggerated, though, the Mutagen's effects are still quite accurate, with a fly mutating to Hun turning into, as he calls "Mutant Turtle FILTH!"
There is also a very literal version of showing their work when the universe starts to be destroyed. It fades to black and white, then blue outlining, before turning to blank white—The exact process (in reverse) of sketching, inking, and coloring an animation cell.
The Wild Thornberrys is actually a very insightful series that puts great detail into describing the behaviors and facts of animals: female lions do most of the hunting, woodpecker finches use tools to catch insect larvae in trees, elephants can communicate through infrasonic rumbles and the adult females live in herds led by a matriarch, komodo dragons use their tongues to smell, stoats use a hypnotic dance to lure rabbits and change fur color in winter, spotted hyenas are ferocious hunters and not cowardly scavengers (and its scientific name is Crocuta crocuta), basengi dogs cannot bark and are used by the tribal Pygmies of Africa to hunt more stealthily, camels store fat in their humps and not water, emus are hunted by wedged tailed eagles, octopi are highly intelligent and can solve complex problems, female hornbills stay inside dens in trees to hatch their eggs while their mates give them food, baby orangutans are dependent on their mothers, hippos have to keep themselves submerged in water during the day because they have no sweat glands and are also the most dangerous animals in Africa and not the cute, lazy bums as Eliza's cousin, Tyler, erroneously thought. Not to mention Small Taxonomy Pools is averted.
Not only did the show go out of its way to teach kids facts about animals, but it also attempted to accurately depict the various peoples and cultures the family encountered around the world, such as the !Kung and Maasai of Africa in the episode "The !Kung and I" and the Incas of Peru in the episode "Nigel Knows Best". In one episode, Marianne and Debbie are puzzled to find the coastal town of Ha Long Bay in Vietnam deserted and shops closed. After a weary day of walking aimlessly around the town, three total strangers invite them into their house in the middle of night and are given flowers, food and gifts, to their confusion. In the end, it's revealed that it was a lunar new year called the Honor of Tet (or Tết Nguyên Đán) where all first visitors after ten get food and gifts in hope that they bring the family good luck for the rest of the year.
Hell, they even put historical geography right in the freakin opening credits by pointing exactly where the family is on Earth right down to the local counties!
The Penguins of Madagascar actually delved into this a lot, usually brought up by Kowalski, the most intelligent penguin of the group and the most analytical. In one episode, a raccoon scares the usually fearless penguins into running away when he shouts "leopard seal!". Assuming they are adelie penguins, they are a common source of food to Leopard seals in the Antarctic. Another episode had the penguins betting against King Julien and his lackeys in a game of catch the flag, and fail every time. They finally get the upper hand when they realize the lemurs can move so quickly because lemurs travel by the tree-tops, rather than on land.
One chimpanzee on the show uses sign language. The staff has consulted with sign-language experts to make sure that each sign and facial expression is accurate.
All Grown Up!, "Runaround Susie": Part of the plot, Susie participating in a language competition, seems to be begging for As Long as It Sounds Foreign. To be fair, some of the words we hear do sound like such. But the overwhelming majority of them are correct.
Courage the Cowardly Dog has one episode where Muriel suddenly de-ages into a 3½-year-old girl from being sucked into a tornado. Courage's snarky computer tells him that the only way to turn her back to her original age was by throwing her into a tornado spinning in reverse. When Courage asks whether tornadoes do spin in reverse, the computer replies, "Only in the Southern Hemisphere, you twit." While the de-aging power of tornadoes is total fiction, the fact that tornadoes in the Northern and Southern Hemispheres spin in opposite directions (counterclockwise and clockwise, respectively) is generally true.
Somewhat surprisingly, South Park. For example, the episode "Le Petit Tourette" actually goes out of its way to point out excessive cursing is only one possible symptom of the disorder and shows characters with other tics. Episodes addressing controversial issues like politics and religion are also generally well-researched, as are their numerous parodies. Though of course, Rule of Funny can cancel anything out.
Henrietta's room after she becomes emo in "Goth Kids 3: Dawn of the Posers" is filled with visual puns and inside jokes about emo culture that must have taken some research on Parker and Stone's part. Besides a conversation about Fall Out Boyplaying the Super Bowl when emos take over the world, easy emo culture jokes are avoided, with a Shout-Out reference going to obscure emo pioneers Sunny Day Real Estate.
In order to pull off a role reversal the way they did in "Red Man's Greed" they have to seriously study the history of native American people.
Say what you will about the old Mega Man TV show, they did a fairly good job at researching the games; most of the character designs, while changed quite a bit, at least kept most of the unique design aspects, and sometimes the entire design. Designs aren't where they stopped, Mega Man's name was "Rock" before he became, well, Mega Man; this fact is somewhat more well known nowadays, but it wasn't back then. Heck, it looks like they paid attention to the fingers of the characters, as in a Bad Future episode, a Mega Man fan actually does this, at about 0:09. People deride the show for being inaccurate, but that's incredibly far from the truth.note Although it kind of is inaccurate in one respect: Proto Man is portrayed as one of the bad guys. While he was an opponent in the third game: he was wasn't necessarily working for Dr. Wily. It's a long story.
Gargoyles was very accurate and detailed in many of the mythologies it referenced, though it changes a lot. Scottish history is also heavily important to the show's backstory—Macbeth's flashbacks, for example, basically combine the historical king's real life with some elements of the famous play (mainly the Weird Sisters) and the show's own themes.
Barring, perhaps, the episode The Hound of Ulster. Good episode, and while not entirely inaccurate, anyone with a passing knowledge of Irish mythology will be scratching their heads.
Futurama may have the most highly educated writing staff on TV (there were at least 4 Ph.Ds on staff during the original run).
Metalocalypse's animation is often carefully synced to the music, with the chord positions and fingering of the guitar parts shown in some detail.
Especially before its original cancellation, Family Guy would often work in references to people, places, products and events that one could only truly appreciate if one was a native of Rhode Island or had lived there for a length of time.
On the other hand however, the show's never been too good on getting the shape of the state right on maps.
Some of the background animals in Almost Naked Animals are a furless tiger with faint stripes imprinted into his skin and a furless bear with black skin and whitish hair strands all over his body.
Rather an Enforced Trope for Fireman Sam, seeing as it delivered An Aesop about fire safety or something related Once an Episode. If they deviated from reality at all it was only as a concession to the limits of their special effects and/or to provide a subtle PSA about what the viewer should do in that situation.
The Tinymon episodes of Johnny Test. The first episode grasped a great many mechanics from Pokémon such as evolving by happiness. The second episode has references to more obscure Pokémon games (most notably Pokémon Colosseum), fandom terminology, and even Digimon.
Tales of Hungarian History is an animated adaptation of Cronica Pictum (with some episodes drawing from the Gesta Hungarorum or legends of various Hungarian saints), and will follow its source materials instead of actual history. Nevertheless, when the plot gets too derailed in terms of historical accuracy, a bald history teacher will show up to tell his version (at one point even getting into a fight with the narrator).
Adventure Time displays a very good understanding of the complicated play dynamics of Magic: The Gathering in their card game episode. For instance, land cards are used to summon creatures, creatures are tapped to activate their abilities, and the spell cards used have effects present in the real game.
The writers actually created the whole card game in real life so that when Jake and Finn played it, it would seem like a real game and not just a load of nonsensical gibberish. The game has since been released in real life, with decks for Finn, Jake, BMO and Lady Rainicorn. Interestingly, a game with Finn and Jake's decks is unlikely to play out as it did in the episode.
Nearly any time features a foreign language, the staff does its best to make sure it's portrayed accurately, such as Portuguese in "Blame it on Lisa", when the Simpson family travels to Brazil, or German in "The Heartbroke Kid", when Homer sings the original German lyrics to "99 Luftballons" aka "99 Red Balloons".
In "Mommie Beerest", Homer and Marge are starting to kiss when Marge has to bail out fast. As he sees his lips still locked for a kiss, Homer decides to put them into use by pulling out a trombone from under his bed and playing "Greensleeves". Any trombone player in the audience will notice the animators accurately replicated the moves a real player would make on the instrument's slide.
"The City of New York vs Homer Simpson" took a lot of work from the animators, but they managed to accurately depict New York City, from the traffic density to the architecture. Except for the World Trade Center, as the towers seem to alternate between being parallel to each other and being at an angle as they actually were.
In "The Joy of Sect", many of the Movementarians' tactics and practices are taken directly from Real Life cults including Jim Jones' People's Temple, Heaven's Gate, and the Church of Scientology.
Some of the hand-to-hand fights in Sym-Bionic Titan are very well choreographed and use a lot of authentic kung fu, specifically in "Fortress of Deception" when Lance fights and uses moves taken right out of Wing Chun and Jeet Kun Do.
For a show about one of the world's most irresponsible secret agents, Archer is very good about gun safety. Firing or setting off explosives without proper protection usually renders someone deaf (and usually Archer, going around saying, "Mawp? Mawp?"). One episode shows Cyril being irresponsible with a gun and accidentally setting it off; when Lana takes it from him, she clicks the safety off, ejects the clip, then ejects the round from the chamber, just in case.
Most of the anecdotes about espionage history and "proper" tradecraft are also either accurate or closely based on the truth before the characters mess it up.
In the Batman: The Animated Series episode "Judgement Day", Harvey Dent develops a third personality called "The Judge" that suffers a vigilante complex separate from his other two halves and eventually declared the dominant Harvey "guilty". People with Dissociative Identity Disorder/Multiple Personality Disorder very commonly have more than one extra personality living in their mind, and it's also not unusual for one or more of the identities to want to kill one another.
Minor villain Baby Dahl appears to be perpetually a child of approximately six. This is indeed a rare condition, most famously carried by Gary Coleman. Dahl also has an "adult" voice she rarely uses — the result of practicing such a voice, rather than puberty. The episode also features her post-fame failure, an all too common trend among child stars.
Killer Croc's skin condition is real, though exaggerated for effect.
A subtle example: In the beginning of Oggy and the Cockroaches: The Movie, Oggy evolves from a microbe into a cat. If one looks closely, after he becomes a jellyfish, he evolves into a worm-like thing (Possibly a Pikaia) and into an eel (Possibly an Agnathan fish).
Patrick's stupidity came about as a result of the fact that starfish don't have brains in real life (though sponges are brainless as well, Spongebob having one was just a case of Art Major Biology and Rule of Funny).
Spongebob's budding and filter feeding are actual biological processes used by sponges, as is the fact that Spongebob is (according to Word of God) asexual.
The show has shown a few times and even used as a plot point the fact that Spongebob and Patrick can regrow their limbs, which both sponges and starfish can do in reality.
In one post-movie episode, Patrick severs his hand after becoming addicted to karate, only for him to grow a new hand and the old one to grow a new Patrick. While making for an odd joke, regeneration in starfish does actually occur like this.
In another episode, Squidward mentions eating his own tentacles if starving, which is an actual survival mechanism of octopi.
Mr. Krabs's greed and position as a fast-food restaurant owner both tie in to the ecological niche of crabs as scavengers.
The stock footage used for an infant Spongebob in "Your Shoe's Untied" is of a real-life sponge offspring.
Bikini Bottom is based on the real-life Bikini Atoll in the Pacific Ocean, hence why whenever the show needs stock footage of a large explosion, they constantly use footage of an American hydrogen bomb test conducted there during the Cold War.
Unlike the other animated adaptions, The Adventures of Super Mario Bros. 3 gets a surprising amount of detail right from the games. The power-ups work exactly as they're supposed to unlike The Super Mario Bros. Super Show, right down to referencing rare power ups like the P-Wing and the Kuribo's Shoe (albeit renamed "Karubi's Shoe"). The disguises Mario and Luigi wear in "Reptiles in the Rose Garden" bear a great resemblance to the Hammer Suit as well. They even had the rulers of Desert Land, Giant Land, Sky Land and Ice Land make appearances, though they're given different appearances from the game. Several episodes even refer to King Koopa as Bowser, making it the only Mario cartoon to ever use his American name, once by Bowser himself! Series concept art even revealed plans to incorporate the Tanooki Suit into the show, but it never came to pass.
The Scenery Porn of the opening scene, as well as many of the show's backgrounds, is very accurate to actual Oregonian landscape.
As said before, almost every real-life animal seen living wild in Gravity Falls is actually native to Oregon, including the somewhat obscure purple finch.
The goat that lives near the Mystery Shack has rectangular pupils, just like goats in real life.
In "Northwest Mansion Noir/Mystery", the mudslide that killed the lumberjack was the result of the deforestation that ensued from him building the Northwest mansion. Deforestation can cause mudslides, because the lack of trees destabilizes the soil, so whenever it rains in a treeless era, the ground becomes saturated and slides.
For all the stereotypical paleontological inaccuracies present in "Land Before Swine", the episode did get quadrupedal pterosaurs right and portrayed Ceratosaurus with laterally-flat horns.
The beavers from "Legend of the Gobblewonker" have yellowish teeth like real beavers.
In "Little Dipper", Dipper feels insecure because Mabel is revealed to be growing faster than he is, despite them being the same age. This makes sense: as anybody with a similarly-aged sibling of the opposite sex can attest, there is an awkward phase growing up caused by the fact that girls hit puberty earlier than boys.
Fans often say Dipper and Mabel have a 'heart', or more 'heart' than the other pair of twins, Stanley and Stanford. Turns out that opposite gender twins are a lot more accepting and open-minded than same gender twins.
Subconsciously or not, Looney Tunes does this with the opening chase sequences of many a Road Runner short (when the predator is able to catch up to his prey so easily). A real coyote can top out at 38 mph while a real road runner can top out at 20 mph. Of course, Hilarity Ensues starting with the little burst of speed the Road Runner puts on.
While not always the case, some shorts display the actual scientific names of the roadrunner and coyote (Geococcyx californianus and Canis latrans respectively).
Steven Universe has an alien race made of gemstones. While a lot of astrology research gets used (like rose quartz being associated with healing, and the Rose Quartz character having healing powers), it can go down to crazy levels of detail. Lapis Lazuli is a cracked gem we meet early on that befriends the main character Steven by making fart jokes. In real life, a lapis lazuli stone absolutely reeks of sulfur when broken or ground to powder. No one but someone that works lapis or knows someone who does would know this, but there it is.
A specific example: A character mentions that a drill to reach the center of the Earth would need to withstand up to 360 gigapascals of pressure and 9800 degrees of temperature. 360 gigapascal is the current upper estimate of the pressure at the inner core, and 9800 is its actual temperature in Fahrenheit degrees.
The Venture Bros.: General Triester is a Thaddeus "Thunderbolt" Ross Expy who thinks he's turning into a Hulk; a fitting reference to the character that Ross is often chasing. It's a ruse at first, but when he actually transforms he's a clear reference to the not nearly as mainstream Red Hulk which is immensely fitting as that's who Ross does eventually transform into.
Penn Zero: Part-Time Hero: The main character's Aunt Rose and Uncle Chuck own a pet chinchilla, which is shown giving itself a dust bath like chinchillas in real life.