Lyrical Nanoha/YMMV

YMMVs for the franchise as a whole: (for specific ones go to the corresponding season's YMMV page)

 * Audience-Alienating Premise: It's a Magical Girl series aimed at young adult men. Moe is de rigeur for most anime, but the cutesy imagery can be a turnoff for Western audiences that don't look beneath the surface to the action series within.
 * Broken Base: With the exception of A's, which is considered an Even Better Sequel, pretty much 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.
 * Striker S caught flak for having a 10 year timeskip, thus losing most of the lolis. 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.
 * Sound Stage X was basically a continuation of Striker S... with no characters introduced before that season making any appearances. People who were not fans of the new characters did not take it well.
 * Vi Vid 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 antagonist so far. 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.
 * And then there's Force. If Striker S broke the base, than Force Starlight Breakered what was left of it. Running concurrently with Vi Vid, 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 seem more than a little broken and the weapons and armor designs are now approaching Warhammer 40000 levels of batshit insane. People think it's either the most awesome thing ever or a Dork Age that never happened.
 * All of this is just from the main series. If we add the alternate continuities, we can also mention:
 * The movie, 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 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 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 Fate Stay Night crossover, which disappointed people who were expecting something serious and longer than a one-shot.
 * TheBattleOfAces 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 have a stronger AI, great amount of playable characters, and a good story with good character development.
 * Previews and Info started showing up for the Second Movie base on A's. People are already complaining about the changes such as replacing  Some fans are saying "Please let this be good." others are thinking "It cannot be as good as the original TV Series. How worst will it get?"
 * Cargo Ship:
 * 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.
 * [[media:[[S Hx A]]_9930.jpg|Sacred Heart/Asteion.]]
 * Crowning Music of Awesome:
 * The insert songs from the first three seasons "Take A Shot", "Brave Phoenix" and "Pray". They all herald Fate's definitive moments for the season and are all sang by her VA appropriately enough.
 * Hayate's theme "Snow Rain". It sounds like a gentle lullaby, yet has a kind of majestic beauty to it, especially when those violins kick in.
 * The BattleOfAces instrumental arrange of "Eternal Blaze" - the opening theme for A's.
 * 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 Spinoff, to the point where anyone looking for Triangle Heart 3 is probably just there to see Nanoha in a strange alternate universe.
 * Memetic Mutation / Fanon:
 * Blood Knight / Sociopathic Hero: Nanoha's in-story enthusiasm for magical combat tends to be exaggerated into outright bloodthirstiness by fans. All the "White Devil" fanart where Nanoha is drawn as an Ax Crazy Stepford Smiler and Memetic Molester of Fate.
 * Cute and Psycho: Due to her whole Defeat Means Friendship shtick, Memetic Mutation has resulted in Nanoha being turned into this.
 * "Befriend" as a euphemism for "beat the living crap out of".
 * More Popular Spinoff: Of Triangle Heart.
 * They Wasted a Perfectly Good Character: YUUNO. In a series so focused on how the ancient civilizations and technologies of the past are enormously impacting upon the present day, having an archeologist, scholar and librarian of ancient knowledge in the cast would seem like a great idea. If nothing else, Yuuno could have continued his roll as Mr. Exposition in Striker S, 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.
 * Unfortunate Implications: Though this probably isn't the writers' intention, Nanoha's method of befriending people might give some of the younger viewers (read: those in the 4-9 year-old demographic) the idea that it's acceptable to beat the crap out of somebody in order to prove that you're right and they're wrong.
 * Values Dissonance: The TSAB makes ample use of grade-school children as soldiers police officers. This is somewhat mitigated by the fact that every single child to ever appear in the series is Wise Beyond Their Years and the vast majority of the TSAB's mages are adults, but it still rubs some people the wrong way.