1. Until Season 5 came, I really didn't like Fluttershy as I thought her character had stagnated since season 2 and was used by the staff mostly for gimmicks to attract attention (Flutterbat) and needed Discord to maintain any relevance. Now she's in a better spot, but she's still my least favorite of the mane 6.
2. I was never enamored with Derpy. I always thought she was overrated as heck considering how popular she is.
3. I never cared for any of the background ponies for that matter as I feel they were mostly popular for having one gimmick and fans took it from there for their own personal interpretation.
4. Limestone Pie >>>>> Marble Pie as Limestone is a far more interesting character and I like her design more. Sorry I stole this one, Supernes
5. Marble Pie is Fluttershy 3.0 without the character depth, Coco Pommel is of that same boat only a little more developed at least, and I'm sorry I stole this one from ya, Megas
6. Princess Luna is my least favorite princess as I don't like how immensely popular she is to the point a few have created these irrational trends in the fandom to either make her look good to their view or justify her turn for Nightmare Moon. Yes I' am especially bitter about her popularity as a desperate Celestia fan.
7. According to EQD, Do princesses dream of magic sleep to me proves that Luna doesn't need to have a good episode to gain a high favor in popularity due to the fact she's Luna. Yes, I'm not happy about it.
8. It annoys me how much hate certain characters receive like Rd for MMDW, Rarity in Sonic Rainboom, Pinkie Pie from Filli Vanilli, for actions they were punished for and not acting perfectly nice or so and are remembered more for that than their more awesome moments. As they said, you can be a saint, but commit one bad thing and you'll be remembered for that.
9. I have no idea why Flash should be so hated today as the threat of a damaging romance seems to not have come to fruition. Give him a chance to be a character instead of a cookie.
10. I'm not happy with Starlight Glimmer's turn for good as it was rushed, skipped over how fell her intentions were in the s5 pilot, her reasoning to turn only made her look like some spoiled child at best, never actually convinced her beliefs were wrong so even more reason for why she shouldn't turn against her zealotry, and I didn't like how she managed to beat Twilight, Celestia's personal student trained by her to defend Equestria, considering she only had the ability to remove cutie marks as anything of note to her powers and her ideology shouldn't have motivated her to be this all powerful unicorn that can beat Twilight. Starlight Glimmer was a villain sue in the S5 finale.
11. I prefer the prospect of the Alicorn baby over Starlight Glimmer's reform as at least the baby was built up better than Starlight's reform has been. There's still hope for her still and I can be wrong however.
12. More Raridash, Raripie, Flarity, Flutterpie, and Appleshy please.