Hi, it me Fluttershy or Flutters or whatever you wish to call me. I'm going to talk about how I see each pony. Excuse any grammar mistakes, I'm on a tablet with horrible auto - correct.
Twilight Sparkle is the main pony of the show. I personally like her fine, she not my absolute favorite at times because of how dramatic she can get over simple things. For example, in "Lesson zero" she overreacted. Other than those few times, I think she a great character. I relate to her love of reading, although not to the extent of her. Over all, she is a great character.
Rarity is the only unicorn out of the mane six because Twilight is an alicorn. She is usually my least favorite because of her tendency to be overly dramatic. I also just don't relate to her much, I'm not a fashion type. I don't hate her though, she still an ok character.
Rainbow dash is in the middle of my favorite list. I don't always like her bragging and over-confidence, but I relate to her tom - boyish personality. She is always there for her friends and represents her element well. I like watching her stunts and tricks and laugh at her sarcastic and blunt ways.
Fluttershy is one of my favorites, her shyness and quiet personality gives her a innocence that makes her adorable. I relate to her shyness and love of animals. I would do anything for an animal just like she would. I think she one if the best characters.
Applejack is a strong female character. She is hard-working and independent and a great role model for any young girl watching her. She would do anything for her friends or family. I relate to her farm lifestyle since I lived on an acreage for about 6 years.
Pinkie pie is probably at the top of my list. I relate to her hyper energetic personality. I'm extremely hyper, silly, and energetic around my friends. That's also the reason my friends don't trust me with sugar, lol. Pinkie is a child - like Character.
All the characters are good in their own ways to me.
Let me know in the comments what other characters you'd like to hear a review of!