YMMVs for the franchise as a whole: (for specific ones go to the corresponding season's YMMV page)
Americans Hate Tingle: A Magical Girl series aimed specifically at young adult men may be marketable in Japan, but it's a different matter in North America. While the franchise does have a dedicated American fanbase, it's not as big as it is in Japan and Geneon's English release of the first two seasons bombed in terms of sales; it's likely that most adult male anime fans in the U.S. would take one good look at the cutesy imagery and run for cover. As a result, nothing else from the franchise was officially released in North America until Discotek Media rescued the license in 2023.
Raising Heart/Bardiche. They've had Anthropomorphic Personifications in fanon even before A's introduced the ridiculously human programs and the concept of unison devices.
Contested Sequel: With the exception of A's, which is considered an Even Better Sequel, any other entry into the main continuity has left the fandom polarised. It doesn't help that the author is constantly tinkering with the established formula in very unsubtle ways.
Magical Girl Lyrical Nanoha StrikerS caught flak for having a 10 year time skip and aging up most of the characters. It moved the setting away from Earth and shifted focus from the previous main characters - demoting several to extras in the process - to a bunch of rookies and a lot more non-essential background characters. The Numbers cyborgs probably got the most heated debates among the fandom as to whether they were credible antagonists compared to the very powerful rivals from seasons one and two. They were also not as well-developed as previous antagonists, probably because there were so many of them. The third season was twice as long as previous seasons, but rather than using that extra time to develop its enormously expanded cast or give screentime to those characters inexplicably shoved out of the picture, the writers instead devoted most of the episodes to training the newbies and discussing military policies.
StrikerS Sound Stage X was basically a continuation of Magical Girl Lyrical Nanoha StrikerS... with only one minor character introduced before that season making any appearance. People who were not fans of the new characters did not take it well.
Magical Girl Lyrical Nanoha ViVid was the first installment to shift from anime to manga, and a monthly one at that, so it already had a strike against it before it even started. Then it turned out it was a Lighter and Softer take on the series with plushy devices, no interdimensional incidents, Magical Girl tropes played straight and more lolis and loli fanservice than ever. It actually reads more like a shonen series with magical girls... and no real antagonists. And then it put the breaks on whatever plot it had going to do a lengthy Tournament Arc and introduce a bunch more new characters. People who liked the changes in StrikerS were disappointed, but in Japan where moe is the law it's the most successful entry in the franchise yet.
ViVid Strike! sent waves throughout the fandom with its very announcement considering the fact that it's a sequel to Magical Girl Lyrical Nanoha ViVid (which as previously stated is a Contested Sequel in its own right). It also didn't help that, at the time, the third Nanoha movie was still in limbo which angered more than a few fans. Things got even worse when it was seemingly confirmed that, much like StrikerS Sound Stage X above, it was a sequel using only new characters and ones introduced from Vivid meaning no Nanoha or Fate (which also makes it the third entry in a row without the two as main stars). Now that the series has finally been released initial reaction seems to be split between those who like the new characters and appreciate the Deconstruction of some Nanoha trope stables or others who are sick and tired of the franchise no longer being about Nanoha and have no interest in the series.
And then there's Force. If Magical Girl Lyrical Nanoha StrikerS broke the base, then Force Starlight Breakered what was left of it. Running concurrently with Magical Girl Lyrical Nanoha ViVid, it went completely the other way, all but ensuring that fans of one series hated the other and vice versa. It dropped most magical girl tropes altogether, introduced a bunch of new characters yet again, including an angsty male lead, which was the last thing anyone expected. It only keeps getting Darker and Edgier - innocent people are dying in bloody ways, antagonists are killing indiscriminately for fun, fan-favourite characters are being curb stomped left and right with powers that, in taking the previous season's Anti-Magic up to eleven, seem more than a little broken and the weaponsandarmordesignsarenow approaching Warhammer 40,000 levels of batshit insane. People think it's either a natural Sequel Escalation of the themes StrikerS started us off on and thus the most awesome thing ever or an Audience-Alienating Era that never happened.
All of this is just from the main series. If we add the alternate continuities, we can also mention:
The Movie 1st, which was accused by some of being an unoriginal rehash of season one with half the plot and twice the explosions and cutting out pretty much anyone that wasn't Nanoha, Fate or Precia. Others liked it for exactly the same reasons.
The Movie 1st manga, which later turned out to have little to do with the movie and more in common with the light novel. It was widely decried for the perceived change in the character of Nanoha - or Emoha as this version is known to the western fans - and generally trying to be too dramatic with the brutal fight scene between Nanoha and Fate that lasted for most of the second volume. And despite being an Alternate Universe that changed many things along the way, it still ended the exact same way as the original anime and the movie, leaving many to wonder what the point of it was.
The Movie 2nd A's was accused by many of butchering the lauded A's storyline. People complained about the changes such as: replacing Nanoha and Fate's reunion from Big Damn Heroes to hugging; having them completely defeated in the first encounter with the Wolkenritter; removing Yuuno from the battle; teasing a fight scene with Lindy that gets promptly aborted; Reinforce trying to kill Fate and Nanoha, without a good reason this time; Nanoha doing significantly less well against Reinforce; and of course, removing the Liese twins and the Graham subplot altogether.
The Fate/stay night crossover, which disappointed people who were expecting something serious and longer than a one-shot.
The Battle of Aces was generally well-received for shifting the focus back to the A's characters and the introduced Evil Twins of the main characters became popular enough to be included in the sequel, but even most of its fans admit that it was mediocre in terms of gameplay.
The Sequel to the above game The Gears of Destiny almost broke this trend. The game has a stronger AI, a great number of playable characters, and a good story with good character development. However the manga cast contributed next to nothing to the overall main story, and the ending used Laser-Guided Amnesia and removes all the Original Generation characters from the timeline until at least Magical Girl Lyrical Nanoha ViVid. It feels like they were trying to invoke In Spite of a Nail to make this timeline identical to the main one. It left the feeling of The movie manga all over again.
Ensemble Dark Horse: Despite suffering of Chuck Cunningham Syndrome, Yuuno is pretty popular among some fans, as he often appears in many fanarts and fanworks. In one popularity poll for ViVid, Yuuno managed to get 13th place despite appearing only in a single panel at the time.
Friendly Fandoms: Fans of Gundam have been noted to enjoy Lyrical Nanoha. The fact that many character designs are Shout Outs to various Gundam designs and the main characters shot giant laser beams at each other that wouldn't look out of place in said Gundam shows naturally help. A lot of Mecha fans are open to the show appearing in Super Robot Wars, in spite of the lack of actual mechas (though the show does have Battleships).
Hilarious in Hindsight: Would you believe this was the prototype for the series? If you've watched the show for any length of time, the sight of Nanoha waving around that puny heart-shaped wand alone will be enough to make you crack up.
Just Here for Godzilla: Subverted. Before the first season's Growing the Beard moment, viewers were expected to just be there to see cute little Nanoha from Triangle Heart 3: Sweet Songs Forever in a strange alternate universe. They were quickly disproven when Nanoha got more viewers than the Triangle Heart 3 OVA. Ever since Nanoha became the perfect example of More Popular Spin-Off, to the point where anyone looking for Triangle Heart 3 is probably just there to see Nanoha in a strange alternate universe.
Memetic Personality Change: Due to her Love Martyr status and stubborn refusal to hold any kind of ill will towards her abusive mother, Fate is often portrayed as a memetic masochist who loves to be wipped, electrocuted and generally punished. Needless to say, this fits well with the merciless White Devil interpretation of Nanoha.
Memetic Psychopath: Nanoha's in-story enthusiasm for magical combat tends to be exaggerated into outright bloodthirstiness by fans. After being called a demon and stating that she may as well be if that's what will work, she has since been known as the "White Devil". All the "White Devil" fanart◊ where Nanoha is drawn as an Ax-CrazyStepford Smiler and Memetic Molester of Fate started from that. She is also the Trope Namer of the term "yangire", despite that she isn't even a yangire herself.
Rescued from the Scrappy Heap: As time passed, the reception of Precia Testarossa has lightened, especially in presence of the much-reviled Hückebein. First, she got Woobie moments in the Movie 1st, then in Gears of Destiny her spirit made peace with Linith's, and finally INNOCENT showed what kind of mother she would have been had she not lost Alicia. Impressive, when back in the day, she really was the bonafide "most despicable, worst mom ever" with evil acts to prove it.
They Wasted a Perfectly Good Character: Yuuno Scrya. In a series so focused on how the ancient civilizations and technologies of the past are enormously impacting upon the present day, having an archaeologist, scholar and librarian of ancient knowledge in the cast would seem like a great idea. If nothing else, Yuuno could have continued his role as Mr. Exposition in Magical Girl Lyrical Nanoha StrikerS, Sound Stage X, ViVid and Force, considering that no one would be better qualified to explain about the Belkan Reunification War, the Sankt Kaiser dynasty, the Saint's Cradle, the Hegemon Klaus and his relationship with Olivie, Queen Ixpelia and the Mariage, and perhaps even the Bible of the Silver Cross and its Eclipse Virus.
What Do You Mean, It's Not for Little Girls?: It may seem like a typical Magical Girl show aimed at young girls on the surface, but its main target audience is adult men; the series' promotional materials and manga adaptations are printed in seinen magazines and it began its life as a Spin-Off of the H-GameTriangle Heart 3: Sweet Songs Forever. The first season even has some fanservice; the next ones less so. In some countries they removed the fanservice and marketed it as a shonen show, though they still left in all the cases of child abuse by the villains. Even though it's a magical girl series, it's very heavy on the sci-fi and seems more like a Gundam series at certain points—intentionally, after one of the writers noticed that Nanoha's Barrier Jacket made her look like a moe Gundam. Later installments take away the Magical Girl elements and put more emphasis on the sci-fi, making it much more obviously aimed at men.
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