TWILIGHT: "Okay - why am I wearing a bowler hat?"
PINKIE: "Perfect silly question, my dear Twilight. Because the obvious answer is..."
APPLEJACK: "...there is no answer, is there, sugarcube?"

One of these things is not like the others,
One of these things just doesn't belong,
Can you tell which thing is not like the others
By the time I finish my song?

FLUTTERSHY: "It's exactly this kind of weirdness that put me off poison joke. Though sometimes I mix it into Angel's carrots when he's been misbehaving."

RARITY: "Do - You - Have - Any - Idea, how long it took me to clean my coat and mane of all this desert dust and bit of cacti! Twice as long as it should have, with Pinkie's words still ringing in my ears! Oh, darling, you'd better believe I let Rainbow Dash have it!"

RAINBOW DASH: "'Unicornia?' The name is Pegasopolis!"

DIAMOND DOG: "My... precious..."
RARITY: "Oh, please, not-darling, that reference is so overdone."

APPLEJACK: "...Y'know, I don't think the layout artist and animator of this here shot thought about the implications it has as a still image..."
APPLE BLOOM: "What d'ya mean, big sis?"
GRANNY SMITH: "Git outta here, you young whippersnappers, before those there creepy grins of yours give ma granddaughter the wrong impression!"

PINKIE PIE: "...yeah, I don't really like looking back at this phase of mine either. Let me tell you, I was really wacko! If I saw any of my friends acting that way, I'd have them committed! Maybe let them out on weekends for a bit of fresh air."
[Rainbow pushes away with her foot a filled-out asylum form]

GRANNY SMITH: "Eh, what were we hugging for here again, Apple Bloom?"
APPLE BLOOM: "Don't ya remember, Granny Smith? I had a crisis of faith and didn't want to bring you to school, so I pretended to be sick, tried to speed up the harvest, controlled you while you were asleep, and faked a message from Uncle Apple Strudel!"

RAINBOW DASH:"Heh, looking back at this, Twilight, you might say that you needed help learning how to train your dragon!"
TWILIGHT: "Oh, sweet Celestia, reverse my alicornhood and kill me now..."

DISCORD: "Finally! Oh, you silly little ponies have no idea how infuriating it's been to sit on the sidelines while you all deliver uninspired opening zingers! Well, except for Pinkie, that meta one back for 'Feeling Pinkie Keen' and Twilight's response was gold. Now, I can show you all how it's really done - "

REMANE 5: "Surprise!"
RARITY: "Wha...! But, I... what are you all doing here? You're cutting into valuable screentime for me to chew the scenery! I was saving all that for the episode's last third!"

TWILIGHT: "Would you look at that, Spike! Our opening screenshot shows off that most useful of animation principles - smearing! Okay, it's mostly wind, but it counts! How often do you see that in Flash?"
SPIKE: "..."
TWILIGHT: "...you don't know what smearing is, do you?"
SPIKE: "...No..."