Now that I've seen every episode, I thought it would be fun to tackle this old meme (hat tip to
earthstar_moon ).
Day 1 - Favorite character from the mane cast.
It's really hard to pick one because I like them all for different reasons. But if I had to pick one, I'd pick Rarity.

When I started checking out this series, I never expected Rarity to be my favorite. But the writers did such a great job giving her dimension beyond the "shopaholic/rich bitch" stereotype that you normally associate with a fashion-obsessed character. I love that she's an artist and a businesswoman who works hard to EARN all the nice things she has (now that I think about it, how does Twilight earn money being a student? A grant from Celestia? Are her parents sending her an allowance?).
Anyhoo, I also love her because her character is really funny (props to the voice actress) and she has all the best songs.
The other days
Day 1 - Favourite character from the mane cast?
Day 2 - Favourite and least favourite episode?
Day 3 - Favourite cutie mark?
Day 4 - Favourite background pony?
Day 5 - Favourite animal featured in the show?
Day 6 - Least favourite from the mane cast?
Day 7 - Favourite and least favourite song?
Day 8 - Favourite cutie make crusader?
Day 9 - Which pony do you relate to the most?
Day 10 - Best and worst trait of Twilight Sparkle?
Day 11 - Favourite Twilight Sparkle scene?
Day 12 - The first episode you saw?
Day 13 - Favourite cutie mark story? (from Cutie Mark Chronicles)
Day 14 - Favourite quote?
Day 15 - The best lesson Twilight has learned?
Day 16 - Best and worst trait of Rarity?
Day 17 - Favourite Rarity scene?
Day 18 - Best and worst trait of Rainbow Dash?
Day 19 - Favourite Rainbow Dash scene?
Day 20 - Best and worst trait of Applejack?
Day 21 - Favourite Applejack scene?
Day 22 - Best and worst trait of Pinkie Pie?
Day 23 - Favourite Pinkie Pie scene?
Day 24 - Best and worst trait of Fluttershy?
Day 25 - Favourite Fluttershy scene?
Day 26 - What are your views on the Friendship is Magic fandom?
Day 27 - How has the show helped you?
Day 28 - What would your cutie mark be?
Day 29 - Would you be an earth pony, a unicorn or a pegasus?
Day 30 - Thoughts of the show in general
Day 1 - Favorite character from the mane cast.
It's really hard to pick one because I like them all for different reasons. But if I had to pick one, I'd pick Rarity.

When I started checking out this series, I never expected Rarity to be my favorite. But the writers did such a great job giving her dimension beyond the "shopaholic/rich bitch" stereotype that you normally associate with a fashion-obsessed character. I love that she's an artist and a businesswoman who works hard to EARN all the nice things she has (now that I think about it, how does Twilight earn money being a student? A grant from Celestia? Are her parents sending her an allowance?).
Anyhoo, I also love her because her character is really funny (props to the voice actress) and she has all the best songs.
The other days
Day 1 - Favourite character from the mane cast?
Day 2 - Favourite and least favourite episode?
Day 3 - Favourite cutie mark?
Day 4 - Favourite background pony?
Day 5 - Favourite animal featured in the show?
Day 6 - Least favourite from the mane cast?
Day 7 - Favourite and least favourite song?
Day 8 - Favourite cutie make crusader?
Day 9 - Which pony do you relate to the most?
Day 10 - Best and worst trait of Twilight Sparkle?
Day 11 - Favourite Twilight Sparkle scene?
Day 12 - The first episode you saw?
Day 13 - Favourite cutie mark story? (from Cutie Mark Chronicles)
Day 14 - Favourite quote?
Day 15 - The best lesson Twilight has learned?
Day 16 - Best and worst trait of Rarity?
Day 17 - Favourite Rarity scene?
Day 18 - Best and worst trait of Rainbow Dash?
Day 19 - Favourite Rainbow Dash scene?
Day 20 - Best and worst trait of Applejack?
Day 21 - Favourite Applejack scene?
Day 22 - Best and worst trait of Pinkie Pie?
Day 23 - Favourite Pinkie Pie scene?
Day 24 - Best and worst trait of Fluttershy?
Day 25 - Favourite Fluttershy scene?
Day 26 - What are your views on the Friendship is Magic fandom?
Day 27 - How has the show helped you?
Day 28 - What would your cutie mark be?
Day 29 - Would you be an earth pony, a unicorn or a pegasus?
Day 30 - Thoughts of the show in general