Fanfic Fuel: Only a couple of talents are ever explored, and lore books list many groups of talents that the movies and the original three novels never even mentioned. There's plenty of room for fanfic writers to make original characters that work in those talents, or just invent completely new talents.
Girl-Show Ghetto: Despite the franchise's general appeal to everyone , the feminine aspects are heavily played up in advertising and merchandise, which may have hurt the franchise in the long run.
Older Than They Think: The word "fairy" was used in J.M. Barrie's original Peter Pan. The word "pixie" was used in Disney's film for no apparent reason. So please don't whine because they use the word "fairy" in this adaptation.
The fairies being subjected to a hurricane, a flood, and an escaped dragon in the span of what seems to be several months or years could not have been helpful to society as a whole, and it's mentioned that multiiple people died in each of those events.
It's also stated in some tie-in material that the movies are prequels to the books, and the reason the movie and book versions of Pixie Hollow are so different has to do with a massive volcanic eruption that happened in the Time Skip between them. This explanation implies that the movie-exclusive characters don't appear in the books because they died in the eruption. It also explains why the book characters act more jaded, aggressive, and self-sufficient than their movie counterparts; of course book Tinker Bell would carry around a knife and have no qualms about stabbing animals to death if she lived through a regional apocalypse.
At the end of Fairy Haven and the Quest for the Wand, when the wand is throwing fairies around, making them grow and shrink, and throwing them into woods. Vidia is described as being "near death" as Ree/Clarion bleeds out on the ground and Terrence falls unconscious.
Again in the aforementioned book, when Rani is trapped in the mind of a bat and only alive as a tiny voice in its head, forced to do whatever the bat does and unable to move.
In Fairy Dust and the Quest for the Egg, when Hook grabs Prilla so tight and crushes her so she can't even scream, and she thinks "not that screaming would do any good."
At least in he books, the fact that any fairy could drop dead at any given moment because a child somewhere stopped believing in them. Think about that for a minute: any person could vanish with no explanation and never be seen again. This includes people like the Queen herself, who essentially runs all of Pixie Hollow herself and whose death would cause major consequences.
Every time something happens to Ree in the books, it raises questions of what would go down if she died. She practically single-handedly runs everything in Pixie Hollow and there's no one who would take her place.
Again in Gail Carson Levine's trilogy: the fate of every existing fairy depends on Mother Dove and her egg, which are both mortal and fragile. When the egg cracks due to a hurricane, it's a major problem that requires an island-wide questbut it's a thin, delicate egg, and could break at any time. It's a miracle any of the fairies are even still alive.
Values Dissonance: In-universe. Peter Pan brings Gwendolyn to visit him, but he has no concept of passing time and changing cultural values, so he expects her to behave just like Wendy did. Gwendolyn, meanwhile, has no interest in playing mother to the Lost Boys or cleaning up their messes, and she doesn't know or want to learn how to darn socks. Peter is confused and surprised by this.
What Do You Mean, It's for Kids?: The books have their moments, especially Gail Carson Levine's trilogy. For an innocent series about fairies, it has a surprising amount of blood, gore, and character deaths. Of note are the scenes where Rani's wings get cut off, Prilla bites Captain Hook until he gets so afraid of his own blood that he drops her, Tinker Bell stabs a fox in the throat, the wand injures the main cast until Ree is bleeding out on the ground and Vidia almost dies, and random fairies die (sometimes of disbelief, but often because an enemy is making them burn or drown to death.)
Crack Ship: For a while, Queen Clarion was shipped with the Minister of Spring, until Secret of the Wings introduced Lord Milori and revealed that she and Lord Milori are an Official Couple.
Almost always Vidia, though less so in The Great Fairy Rescue (later stories turn her into a more grouchy protagonist than the villain), and Ginger in Dulcie's Taste of Magic.
Arguably Clarion in Fairy Haven and the Quest for the Wand when she used her wish to shrink the hawks so they wouldn't eat fairies anymore. This is treated by others like it was an act of cruelty, even though hawks in this universe are sentient and perfectly capable of surviving without eating fairies but do nevertheless.
Vidia, though she was only an antagonist in the first movie. At least, talking about the evil part, that is.
Fandom-Specific Plot: An original fairy character being a fire-talent and unintentionally causing trouble by either being an omen of doom or Power Incontinence. Became Ascended Fanon when Never Girls introduced the Pixie Hollow's first ever fire-talent fairy, Necia.
Fanfic Fuel: Every 972 years, Gruff must go through something similar to Legend of the Neverbeast. How many Fawns and Nyxes has he known throughout the eons? How many more will he know in eons to come? Will the fairies he encounters the next time he wakes up even understand what Fawn wrote about him, or will they be as confused as Nyx was?
Fanon: Make no mistake, you may hear that Tinker Bell was born from Wendy's first laugh, but this is fanon. This largely died out by the time of Secret of the Wings, just as Periwinkle was introduced.
It would appear that Terence was supposed to be Tink's love interest, but a significant portion of the fandom thought he was a pretty boy caricature (he's simply nice to the point of blandness, with his only real quirk being that he's a Neat Freak), and thought that Tink/Bobble was much more appealing.
Tink/Vidia has an immense following as well. There's a good number of fanfics dedicated to them. Not surprising, really. Just take a gander at the Les Yay page.
Tink/Silvermist also seems popular for Silvermist being a supportive friend to Tink.
Foe Yay: Tinker Bell and Vidia (though only apparent in the first movie). Rosetta and Rumble in Pixie Hollow Games, and Fawn and Nyx in Legend of the Neverbeast have possible subtext as well.
Genius Bonus: At the end of Legend of the NeverBeast, Fawn checks Gruff's heartbeat. It's not commented on, but it's slower than normal, which is how Fawn realizes that he's about to hibernate.
Tinker Bell having a distant sister who wears all blue, has a pale hair colour, and ice-based powers. Sound familiar? To add to the coincidence, when Tinker Bell is hiding in the basket to cross the border, Clank and Bobble cover for her by pretending that they're sad to see the basket go. Fairy Mary's response? "Just let it go!" Periwinkle's hair even looks near identical to several of Elsa's prototypical hairstyles.
Silvermist, the water-talent fairy seems pretty into Tinker Bell. Or at least more affectionate than is "proper" for two platonic fairies! She greets Tink by stroking her nose and saying, "Easy... Silvermist's got ya."
If we're going to get into Les Yay for this fandom, that's hardly the most prominent example... the high ratio of female characters does increase the possibilities. Vidia & Tinker Bell can easily be turned into a Belligerent Sexual Tension situation, especially with Vidia's constant use of "sweetie" and "dear".
In The Great Fairy Rescue, Vidia seems like the only fairy who's genuinely worried about Tink after she gets captured. Sure, Tink's other friends care about rescuing her too and what Tink's in isn't a laughing matter, but they at least soften the situation they're in with humor. Vidia doesn't. Throughout the journey, she's just so... concerned and anxious about her. It seems less like someone worrying about their friend and more like a spouse worried about their lover...
To add to that, Vidia actually helped out with a tinker job in building the boat. This is something she probably would have avoided in the past, but she puts that aside just to help Tinker Bell. And then, when the tables are turned with Vidia being the one caught after risking her life for the green dressed fairy, Tink appears to be flying faster then she's ever gone before, like a Fast-Flying Fairy. And, she's the only one of the seven fairies who attempt to stop the car.
Also, when Vidia is freed (thanks to the efforts of Tink, mostly) who is the first person that embraces her? Tinker Bell, of course! The two even twirl a little in their hug before the others join in. Then, at the end, Tink and Vidia share a cup of tea. Oh, and, did we mention that they're practically leaning on themselves when they do so? The whole thing is adorable.
After her HeelFace Turn Vidia gets really touchy feely with Tink, is always the first to console her and tends to stand closest to her. She comes across as having a bit of a crush on Tink.
Come The Pirate Fairy, Vidia gets hit with the Tinker Talent Pixie Dust. This doesn't go well at first, but when she knocks out one of the pirates, she starts to really embrace her switched talent. Tink is also shown to be impressed. Plus the fact they appear to have more interaction here then any other movie, aside from Great Fairy Rescue. Now if only Tink was turned into a Fast-Flying Fairy one of these days...
Close to the end of Pirate Fairy the fairies and blue dust are finally safe. What's the first thing Tink and Vidia do. Hold hands. No, seriously. They hover in front of each other, hands linked, and look into each others eyes until Zarina tries to return the blue dust.
And, if that wasn't enough, at the end of one of the coloring books that was released around The Great Fairy Rescue (called Super Special Coloring and Activity Book) Tink and Vidia seem to be shooting each other bedroom eyes.
At the very end of Pirate Fairy Tink and Zarina are holding hands and staring into each other's eyes as the rest of Pixie Hollow rushes up to congratulate them on their performance.
Tinkerbell and Periwinkle have this despite being twins. Of course it helps that their relationship is played as and compared to Star-Crossed Lovers.
Most of Fawn and Nyx's interactions in Legend of the Neverbeast seem less like a character doing their job and another doing the right thing and, without the context, a lot more like couple chatter, with Fawn being the happy, energetic girl and Nyx being the dry, deadpan one.
In Legend of the Neverbeast, after Tink gets knocked out by Gruff (though this action was to save her, as revealed later), Fawn holds Tink close in her arms, and later is visibly, hauntingly distressed about it, to the point where she gives Gruff up to Nyx.
In Pixie Hollow Games, Rumble crosses this when he shoots Rosetta and Chloe's race car with a lightning bolt. Certainly, it's a horizon crossing in the eyes of his partner, who reacts by throwing the race. Of course, it probably didn't help his situation that Rumble used Glimmer's magic to do it, as he himself can only create thunder, not lightning.
James in "The Pirate Fairy" after he leaves Zarina to drown.
Narm: Nyx's staff/spear/lance, which looks hilariously like a striped toothpick.
In Great Fairy Rescue, Vidia and Tink's reactions to the butterflies that were on display in the human's household. Considering the fact that in the films, they've shown that the insects are all personified and the live butterfly in the jar that Elizabeth's father caught has cartoonish eyes, its mildly shocking to see them dead and on display.
The appearance of big (well, for fairies, anyway) rat on the pirate ship from The Pirate Fairy may causes some audiences freaked out. Especially so if you compare the rat with Cheese, the cute mice in Pixie Hollow.
It's also a little unsettling for some people anytime Tink gets angry, as seen here.
How close Zarina got to drowning in "The Pirate Fairy".
Some people find the idea of mouse milk and cheese disgusting.
The weird Ship Tease that came up between Captain Zarina, an ageless fairy, and her first mate, who is a human adult male. He came across as lovingly admirable of her abilities, even wistful of her, and he was the only one who understood anything she said. Zarina was clearly happiest with him and was the most fond of him. Then he stabs her in the back and you learn for certain that he's Captain Hook.
In Fairy Haven and the Quest for the Wand, when Rani is stuck in the mind of a bat and forced to eat live bugs.
"Flitteriffic!" But other than that, far less than you'd expect.
Worse than that, Vidia of all people is resorted to using these puns! (though only in one short, where she was having a nightmare)
They Changed It, So It Sucks: The film series has little in common with the books, such as making the attire of many of the fairies Color-Coded for Your Convenience depending on their talent, using an almost entirely new cast of characters with slightly altered personalities (such as Queen Clarion being more distant instead of close to her subjects and there being little to no references to the cast from the books), and introducing new lore for marketing reasons (like the winter fairies and alchemy).
Visual Effects of Awesome: The animation in all the movies is far prettier and more detailed than a direct-to-DVD movie series has any right to be.