While I didn't like the first Equestria Girls movie, Rainbow Rocks is probably my favorite thing about the entire series. They turned a poorly written redemption into a realistic slow process where the character tries to better themselves and where others need time to forgive them for their mistakes. It shaped Sunset into my favorite character!
With that being said I really dislike Starlight for the complete opposite process. She never really seemed to care about the things she's done and uses it as a joke in the worst kind of way; I can't tell if it's poor writing or just a bad character in general and that is super frustrating to me. I kind of wish they would just get rid of her and not consider them a new main character.
"Fluttershy Leans In" is an episode that made me think that the writing team was back on their feet! ... until the rest of the season happened. Ouch. So much for character development.
On that same note, re-watching the first few seasons made me realize that Rainbow Dash had a lot of relatable qualities in the beginning, but as the series went on into the later seasons I feel like a lot of those are lost; this could be because of the writing that I mentioned earlier.
The comics are amazing and I'm very sad that the animated series doesn't use any of the content from them. Celestia is a very flat character in the animation, but so very fleshed out in the comics!! I highly recommend reading them.
Chrysalis is the best villain and honestly the most cunning. Discord's actor is amazing, but they still can't top the queen.
I actually like the idea of Twilight becoming an alicorn, but I think that "The Princess of Friendship" sounds very lackluster in comparison to the other princesses and their titles.
Finally, the MLP Movie was absolutely amazing and I cannot even tell y'all how many times I've watched it!