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.
During the segments where Sakura tries to identify the Clow card of the week and their current movement, Kero and Sakura used the cards for fortune telling and determined that 'The Mirror' card is targeting Touya. The fortune telling abillity is never foreshadowed, never used by anyone else (Not even Clow himself) and is never mentioned again.
Broken Base: NIS America's decision to add the Animax dub in their DVDs. Some are happy it's uncut and uncensored and that the voices actually match the characters better, even if the voice acting is a bit shaky, while others claim it to be even worse than the Nelvana dub and wish the latter was included instead.
It also was wildly popular in Mexico, thanks to a really good dub, compared with the English one. It does help that Cloverway managed to get the rights of the original Japanese version from NHK, rather than getting the same rights from Nelvana, despite Nelvana having rights for the whole American continent besides the U.S. and Canada. In fact, the series was widely popular in the whole of Latin America, in part thanks to the Mexican dub and because it was aired at prime time by Cartoon Network in the region, and amongst other anime such as Saint Seiya, Maya the Bee, and Dragon Ball, it found a place in the pop culture, becoming a staple of the 90's generation childhood memories.
Girl-Show Ghetto: For the most part its averted thanks to its engaging characters (and the fact that Tomoyo designs costumes just so she can throw Sakura into them), interesting story, and some dark undertones, though some haters may accuse it of falling into this somewhat due to its normally bright and idealistic nature and in-universe romance...pretty much why Cardcaptors, the edited dub, exists.
Toya tells Sakura that she isn't fit to be a princess, then Tsubasa Reservoir Chronicle came out with Princess Sakura as a main character.
Numerous fanfics had Sakura as a princess with Syaoran as a prince or someone who loves her, and equally vice versa. Come Tsubasa, and that's what happens.
The Sealed Card movie has Sakura playing a princess in a school play and brings in the point of sacrificing one's love to capture Card #53. It doesn't happen, but then, what happens in Tsubasa? More recycling.
Avalon Code has several resemblances to this, which makes Sakura's dub surname Avalon an amusing coincidence.
When Sakura's father speaks to her class about his job, Syaoran shows quite a bit of intrest in archaeology. Come Tsubasa, that version of Syaoran is an Adventurer Archaeologist.
Nelvana and Kids' WB!'s attempts to boost Syaoran as a co-lead in the Cardcaptors dub come off as ironic following his gradual evolution as Breakout Character for the original anime (and CLAMP media as a whole).
Sonomi had a crush on Nadeshiko, but it was one-sided.
The Light and Dark cards.
Jerk Sue: Syaoran is a Deconstruction of this trope in his early appearances, implied to be because he came from a family where his prodigious magical talent led to him becoming arrogant and stuck-up. He's a jerk to Sakura, but she never calls him out for and still treats him like a friend. The result of which is that he's outright baffled by her behavior and changes because of it.
Macekre: The English adaptation known as Cardcaptors was edited and modified in an attempt to downplay the cutesy shoujo factor and moderate it for easier audience consumption across the board. In addition to also being a shoddy attempt at doing so, it was not looked upon favorably by the original fans or many new ones; production and DVDs for the series stopped being made after it was noted the original version released at the same time sold much better.
Mary Suetopia: It isn't a world so straw as to bash anyone for not being a part of their happy land (Mainly because the series doesn't even have a real bad guy), but CLAMP purposely made Card Captor Sakura a place where there is acceptance of all minorities, sexual orientations, children, adults, boys, girls... to set a good example for the children growing up watching it. You'll notice that there are no malicious adults in this series. At all. The few adult characters that start out looking like they might spoil for a fight (for example, Sonomi's aggression towards Fujitaka) are quickly resolved and they join the Big Happy Family).
Memetic Sex God: Clow Reed, if you really think about it. Most of his card spirits are beautiful women, he had a relationship with one of his students, one of his reincarnations runs off with a Miko and another was married to a model, he probably had other girlfriends or a wife or two not mentioned (as his family line has continued), and he had a history with Yue... Clow Reed Really Gets Around.
Misblamed: 4Kids Entertainment often takes heat for Cardcaptors from people who don't know all of the facts. Nelvana itself gets unfairly maligned for the "Syaoran as main character".
Moe: Sakura starts off as a light example, but by the end of the series she is a probable Trope Codifier. Heck, Sakura even won the first ever Saimoe Tournament. (The TV show certainly marks the point at which the anime production companies noticed the Peripheral Demographic that sprang up around characters like her, and their buying power). This is toned down slightly in the Nelvana dub, where she is given a more 'tomboyish' attitude and some of her 'cuter' or more vulnerable aspects are edited out.
Tomoyo also counts to a slightly smaller extent; she also made it to the semi-finals (Top 4) of that very same tournament.
Moral Event Horizon: The Enchantress' practicing dark magic, despite Clow's warnings. It went as well as expected.
Never Live It Down: According to fandom, all Kaho does is seduce her students. This is based on her relationships with Touya, a former student from her time as a student teacher, and Eriol, the reincarnation of a centuries-old sorcerer who only looks like a child so he could blend in with Sakura's class and never was Kaho's student.
Periphery Demographic: Owing in part to the hilarious, cutesy and heartwarming nature of the series (and probably because of quite a bit the Yay subtext too), this show has a surprisingly large viewership of boys, older teens and even middle aged adults, clearly evident from the statistics of any popular video on the internet.
Die for Our Ship: In the fandom just about everyone has been targeted by Shippers at some point or another for being in the way of their OTP. Syaoran, Nakuru, Kaho and Mei-Ling are the preferred victims. There's enough to warrant its own page, and that's not even complete.
Values Dissonance: Sakura asks Eriol about the religious beliefs of the people at the Church. Eriol responds not with a description of Christianity, but with what might as well be a description of Shinto. Sakura is moved when she hears it, and anyone who knows anything about Christianity is hit with a Broken Aesop.
Vocal Dissonance: Nelvana dub decides to give Kero, a cute and tiny little critter, the voice of a 20-something year old man with a surfer tone. The Latin-American and Portuguese dubs are guilty of this too, even though they're known for Superlative Dubbing. Thankfully, the Sealed Card movie and the Catalan dub give him suitable voices for both his plushy and beast forms.
The Woobie: Being a CLAMP work, the large majority of characters have at least some vague tragic aspect to their personality.
Sakura may be the most consistent example throughout the series' run, due to her occasional Moe aspects and more fragile emotional disposition, as well as being unwillingly dragged into the role of Cardcaptor to begin with.
Yukito is one during the Sakura Card arc. Yue is also revealed as one after a flashback shows how much Clow's death hurt him.