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.
Clover's sister, Meadowlark. Likely because of her Cool Big Sis persona and the only sibling dynamic to get fleshed out in the series. She appeared in all of two episodes, and it's common to hear fans wish they could have gotten more of her.
Family-Unfriendly Aesop: "Shop Talk" is MADE of this...and of the worst kind. Hey kids! What did we learn today? Blackmail is the answer to all your problems! *blech*
Germans Love David Hasselhoff: The only plausible reason why two of the ponies from this series got a kiddie ride made after them and the show has seen home video releases in the UK and Australia. And in Australia's case, it was a complete release of all 26 episodes spread across 4 volumes. The series has since had a home video release announced for its home market, the U.S.
Tear Jerker: The song Off You Go from the episode "Gribbet". You try not crying, especially just after losing a pet, or giving away something of sentimental value to someone else.
The Scrappy: Ace is the most hated character for not only treating girls like crap and using them for his own purposes (only made worse by the fact that the show is aimed for girls) but for also being a Jerkass in general.