These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Abandon Shipping: Back when Sunshine first aired, people were confused and disgusted at how the writers treated the pairing of Mikage/Ruby with the utmost seriousness, and far preferred Mikage/Kanon. Cue reveal and fans dropping Mikage/Kanon like a hot potato.
In Lady, Lilian/Cayenne was initially seen as a non-squicky alternative to Momona/Cayenne, but the very early reveal that Lilian and Cayenne are actually siblings turned the fandom off the idea.
Author's Saving Throw: The Blu-ray Selection box of Kira Deco only included 16 select episodes, all of them important to the series' initial plot. However, it causes a lot of Plot Holes as not all the episodes were released due to the series' negative reception.
Awesome Ego: Sunshine would probably lose more than half its entertainment value if it eliminated Kanon's amazingly over-the-top self-confidence.
Awesome Music: All openings and endings are extremely catchy and memorable.
Base Breaker: Jewelina, specifically the Twinkle and Kira Deco versions. Some fans believe she isn't as magnanimous as she appears. In Twinkle, they think she is somehow a bitch for warning Fealina not to go to the human world or that Akari is being forced to clean up her mess. In Kira Deco, they take issue with the fact that she dumped the Dark General and therefore created the main conflict in the show.
Marie Hanazono from Happiness. You love her for being by far the most complex character in the show and the fact that she's the only one to have any meaningful character development, or you hate her because she's an egocentric, one-track-minded, whiny little bitch who butts in a lot.
Better on DVD: Sunshine likely inverts this trope by having its licensed soundtrack removed and replaced with incredibly corny 80s-sounding instrumentals (think as if Giorgio Moroder had been hired to score the anime).
Bizarro Episode: Episode 39 of Sunshine is completely detached from the rest of the season. No one from the regular cast appears save for Labra and Angela (and an easy to miss appearance by Jewelina's fairy assistant). The plot is a replica of 1970's road movies, where Labra and Angela get mistaken for heinous criminals and get chased by the police, then almost enslaved by a circus and finally nearly kidnapped by aliens. And all this junk happened because they wanted to deliver the mail to the end of the world.
When the anime was first announced back in 2009, a lot of Onegai My Melody fans were divided. The hating part think that Onegai My Melody should have a 5th season to compensate for the mistakes of Kirara. The others thought it was great that My Melody was finally put to rest and that it was about time Studio Comet tried something new.
There are also the debates over which season is better. In particular, there are the people who absolutely loved Twinkle and think everything else in the franchise pales in comparison, with other people preferring Sunshine for its funny writing and appeal to older audiences.
With the debut of Lady, camps became neatly divided between supporters of comedic and dramatic Jewelpet (there's also some controversy about where the first series falls in).
The Twinkle OVA is seen as either a good epilogue to the story or creepy otaku pandering.
The loss of the Magical Girl elements. There are the people who got into the anime for this and find it lamentable that it's dropped starting with Sunshine, while others think that it allowed the anime to find its own identity.
Creator's Pet / Canon Sue: Ruby. She's clumsy and irresponsible, but is also The Chosen One, super-powerful and always knows the right thing to say or do. Also gets very little comeuppance for the crap she pulls. (Remember her abuse of Opal in Sunshine? People chastised her, but she never actually apologized, and later even made a speech to Opal which made her seem like she was in the right.)
Contested Sequel: Kira Deco qualifies as this, largely because most complainers belong to the Periphery Demographic and they are disappointed with how much more childish the fourth season is compared to previous seasons, which often went out of their way to appeal to the otaku crowd. Sweets Dance Princess also had some fans in doubt of whether it's a decent first attempt at a film, or just a big shameless ad for the Sweetspets.
Ear Worm: The opening of the first series and both the OP and ED songs of Sunshine.
The song "Strawberry Time" on episode 37 of the first series is even catchier.
The opening for Lady is supremely catchy, sounding like a 90s Spice Girls pop song.
Ensemble Darkhorse: Judging by the amount of fanart, Macaronia seems to have more fans than the rest of the Sweetspets.
Monica Sakura is pretty well-regarded in the fanbase, despite not getting a lot of focus.
Sara might just be the most fanned over character in Twinkle (if not the whole anime series).
Esoteric Happy Ending: Sunshine has this after you give it some thought. Sure, Mikage gets to be with the love of his life forever... but did he even say anything to his parents during those five years? And how are they (and Kanon) going to react when they find out he turned into a Jewelpet?
Germans Love David Hasselhoff: Popular in Hong Kong, though less so than in its home country. The USA, for the most part, barely even know this exists.
The franchise was marketed to hell and back when the first series started airing in Europe, but enthusiasm for it died down a year or so later, with a lot of countries only airing the first two seasons (sometimes, not even the second one). Only Spain and Portugal air seasons after Twinkle now, thanks to the efforts of Luk Internacional (to give you an idea, they also brought the entirety of Onegai My Melody), likely because they have some kind of deal with TV Tokyo or Sanrio.
Twinkle enjoys Western-side success more than any other season, while the others tend to be dismissed, either due to lack of subs or first impressions of childishness.
Growing the Beard: Regardless of whether it's good or not, many people consider Sunshine (specifically, the downplaying of the magical elements and introduction of off-the-wall humour) the point at which the anime grew into its own thing.
And for season-specific moments:
Twinkle has either episode 8 (one of the first major emotional points and instances of character development which the season prides itself in) or Alma revealing herself to the protagonists, which sets the major dramatic plot in motion.
Sunshine has episode 14, which provided the opportunity of showing that, though still a Gag Series at its core, it was entirely capable of writing drama side-by-side with comedy and really set the Love Triangle of Ruby/Mikage/Kanon in motion.
Onegai My Jewelpet Kirara Deco for Kira Deco due to its plot being highly similar to Onegai My Melody Kirara. And note that both of these series are considered the worst incarnations, except that Onegai My Melody Kirara turned out to be a Franchise Killer for the My Melody anime.
Code Dian: Andy of the Rebellion.* In episode 36 of the first series, Dian transformed into a human guy named Andy Samael, who actually looked like Lelouch. Fittingly, he is voiced by Jun Fukuyama which fits his role as a Magnificent Bastard.
Keigo Tatewaki, the lost member of Celestial Being.* Fans had no idea who Tatewaki's voice actor was when the series first aired. Then the ending credits revealed that Mamoru Miyano was doing his voice, which is hilarious considering he voiced Setsuna. Miyano doesn't usually voice Butt Monkeys. Until the gag OVA of the series and some CD Dramas showing Setsuna's humorous side were released, fans were rather shocked with Miyano's role.
Pretending to be Kira Deco-era Angela and Labra and arresting people for saying something which ticks them off (like Fandom Heresy).
"Everything is Ruby's fault."* Because of the reveal at the end of Happiness and Ruby's reputation to cause disaster wherever she goes, fans have taken to joking that the major crisis driving an anime's plot is Ruby's fault somehow. The funny thing is that this is only true of Happiness so far.
"Sasuga Ruby."* Screenshots of Ruby doing or saying something stupid accompanied by this phrase, which means "As expected of Ruby".
Memetic Sex God: Judging by the fanart, Garnet and Macaronia for the pets, and Akari and Kanon for the humans.
Oh God... Let's not get started on Miria... Every single artwork of her, including the NSFW ones totally push her into this status (sometimes mixed with Reluctant Fanservice Girl) and most of them reach disturbingly high levels of popularity.
Moe: Twinkle's character designs lend themselves to this very nicely.
Yamirin from Kira Deco. It helps that she was designed by an in-universe otaku.
Most Annoying Sound: "SAWA! YAKA! SAWA! YAKA! SAWA! YAKA!" would be more tolerable if it weren't repeated loudly and ad nauseam by Hisashi.
Labra's crying can definitely make your ear drums bleed.
Narm: Labra's death in episode 51 of Kira Deco loses all its impact when they show Angela's shocked reaction, which is super-deformed.
Nightmare Fuel: Episode 36-A of Sunshine, with all the characters being replaced by people who look like them but are not them. It's a Paranoia Fuel extravaganza!
Episode 25 of Kira Deco, featuring a village of saury. Coal casts a spell to rot its inhabitants, and we get to see decaying zombie saury as a result. Then the unaffected saury decide to commit suicide by throwing themselves in a fire, to avoid becoming spoiled food. Yes, they do see themselves as food, and think it's a great honor to be killed and eaten by other beings. Even if the show treats the whole situation as absurd, it's pretty freaking horrible when you think about it.
The scene in the movie where Park morphs into his monstrous form will most likely startle first-time viewers.
No Yay: Reaction of the fans who aren't okay with human-Jewelpet romance. There's a reason Mikage/Ruby had a hatedom during Sunshine's airing.
Some people take issue with Momona/Cayenne of Lady, because Cayenne looks a lot like Momona's cousin (who she had a crush on).
One-Scene Wonder: Hilde and Sagan of Twinkle. All they do is fight main characters and lose against them. Apparently, viewers liked them enough that they got to appear in the OVA opening. Gunho did not have the same luck, despite having the same profile, which tells you a lot about the nature of said viewers.
One True Threesome: Some fans are supportive of the idea of Yuuma/Akari/Alma after the huge load of Les Yay between the latter two in the OVA.
Pandering to the Base: Kira Deco is the end result of what happens when something aimed at little girls excessively panders to the periphery demographic. The anime has done this since the beginning, but the first series had small doses of it and Twinkle had a reasonable balance. However, Sunshine truly spoilt the secondary audiences too much (18-year old characters worried about their future, taboo love and a myriad of obscure pop-culture references are a winning combination for otakus, but not for little kids) and shot their expectations for Kira Deco far too high. Hence, the outrage of the secondary audience when Kira Deco turned out to be Lighter and Softer so it'd be more appealing to kids (its main demographic) again. The Blu-Ray Selection box is just another example of surrendering to the periphery demographic.
Pink gets a lot of Costume Porn thrown on her to appease the older (male otaku) audiences.
Twinkle's OVA does this as well, and can get away with it more easily since it's direct-to-video. Where else would you get to see Alma in a leotard?
Periphery Demographic: At first, the entire franchise appealed to girls only. It was with the release of Twinkle that the series started pandering to the older demographic, including otakus. That is because Twinkle has the producer of Tokyo Mew Mew and Nanatsuiro Drops in charge.
Sunshine is well-liked by the older audience, but the main demographic of kids doesn't seem very fond of it (the high school setting probably alienates them).
The Scrappy: Ruby gets this to a lesser extent. Being the mascot and the protagonist does give her her share of haters, due to overexposure. Of course, some do find her genuinely annoying as a character.
Sequel Displacement: Twinkle is by far the most well-known season, to the point where many people think it's the first one made, which isn't helped by the fact that many anime streaming sites mistakenly replaced first series' episodes with episodes from Twinkle.
Lady seems tailored for this with its cast of 4 Petit Ladies and 4 Princes who must inevitably get together sometime in the future (it's canonically mandatory). It becomes complicated when one of the Princes is one girl's brother and looks like the cousin of another. The debates over the ideal combinations that avoid Incest Subtext must be seen to be believed.
Strangled by the Red String: Ruruka/Takumi from Happiness. She doesn't interact with him a lot, and certainly not in a significant way. Yet she decides to give him Valentine's chocolate for some reason. It's a very poorly developed relationship compared with Chiari/Kosuke and Nene/Mouri.
Surprisingly Improved Sequel: From a technical standpoint, Twinkle is a massive improvement over the first series, featuring elaborate backgrounds and color schemes and a sleeker, more professional-looking character design. These improvements carried on to following seasons. It's also generally thought of as much better written than the first series, due to its well-developed characters and emotionally-rending plot.
They Changed It, Now It Sucks: Some people who started with the first series or Twinkle can't really handle the turn for the insane that the anime took starting with Sunshine.
Some people dislike Kira Deco for being Lighter and Softer and much sillier than the seasons that preceded it.
They Wasted a Perfectly Good Plot: The relationship of Kaede and Charotte in Sunshine. Despite being roommates, they're not seen interacting even once in the whole story. It would have been a great opportunity to develop Kaede beyond her relationship with Kanon, especially considering Komachi got such development with Sango.
In Twinkle, Akari possessed by the Battest. We could've had EVIL AKARI. Seriously, picture how epic that would've been. But nooooo, the writers thought it was better to just let her faint...
Viewer Species Confusion: Io and King. The first one is a particular species of rabbit characterized by having droopy ears; it's easy to think that he's a dog, especially in Twinkle, where he forms a trio with two dog Jewelpets; it ended up being lampshaded in Happiness. As for King, he is supposed to be a French bulldog, but his color scheme makes him look like some sort of creature who decided to wear a pink rabbit outfit... with a pig-like tail. Truly the stuff that Mind Screw is made of.
What Do You Mean, It's for Kids?: Every season has its Getting Crap Past the Radar moments, but some scenes in Sunshine honestly seem more like 'Slapping Crap In The Face Of The Radar'. What writer was enough of a madman to dress Jill, Kaede and Komachi in dominatrix outfits? In a weekend morning anime?
Win Back the Crowd: Happiness attempts this by going back to the popular-with-older-audiences style of Sunshine after Kira Deco's failure.
The Woobie: It might be all in her head, but it's hard not to feel for Akari when she's about to break into tears from thinking about how her parents give more attention to Monica and how Monica is better than her at everything she can think of (also, she's cute, so that magnifies the feeling).
Dubs translate "Kanzen Muketsu Bishoujo" (Miria's self-chosen title) as "Kyuper Mega Beautiful", retaining the initials in the process.
The title of episode 30-A of Sunshine was changed from "Look Behind You" to "All The Teacher Iruka's Men" in European dubs. Not only it is a delightful Shout-Out and Parental Bonus, but it also makes more sense in the context of the episode, as the plot is about Sapphie being curious and actively chasing down the men who push Iruka's water tank. The former title is suggestive of Paranoia Fuel, which Sapphie never feels, but it is the reaction that viewers might have with the ending of the episode.
In episode 1 of Kira Deco, Opal calls Ruby 'Baka' and a discussion ensues about how Opal is more 'baka' because the word needs the characters of 'horse' (which Opal is) and 'deer' to be formed. In the Portuguese dub, Opal calls Ruby 'burra', which means both 'stupid' and 'donkey', and Garnet remarks that she is more 'burra' because of the closeness in species between horses and donkeys.