Hurricane Fluttershy

Hands down.

cool mine is the best day ever one.

"You're....going to LOVE MEEEEE!!!!!"

Such an amazing scene. I loved Season 1's mental meltdowns. I wish they would do more of those. 

Twilight: Okay, we'll build an exact replica of Ponyville over there. We've got less than a minute!

Applejack: Ah..wha...wend all the apple...heeby en da boan...*faints*

Rarity: Everypony is laughing at me! I'm nothing but a laughingstock!

Rainbow Dash: *cowering in fear before her performance at the Best Young Flyer competition*

Pinkie Pie: *hair deflates* My friends don't like my parties and they don't wanna be my friends anymore...

I miss stuff like that

Suited for Success, for sure