Ok, let's start with something classy:

I’m gonna stick this bottle up your ass so deep that ponies will start to ask why your eyes are so glassy!

A Kingdom Divided, chapter 2.

What a sick and twisted idea - I like it!

My reaction to this story's description. Or, more precisely, its first sentence.

“Stupid wings, we’re heterosexual, remember?” Rainbow Dash scolded.

The Great Barn Robbery

From this article.

Why not both?

Usually used in discussion about clopfics when someone wants me to choose between two characters or two fetishes.

Assorted quotes from Berry Punch Takes Manehattan, chapter 1:

The opening:

Berry Punch slowly opened one eye. She could swear that her eyelid creaked like a rusty iron door that had been closed shortly after Princess Celestia was born. Her throat was dry like a desert, complete with sand, scorpions and some bearded pony trying to convince his companions that he was just given two stone boards with the list of cool things they totally shouldn’t do.

She took a deep breath, causing a dust storm in her throat, and accidentally destroying a quite promising civilisation which just figured out how to build pyramids. Feeling her lungs expand, she tried to open her eyes again.

“Great,” she whispered to herself, when she finally managed to accomplish that feat. “They put me in a coffin again.”

As someone commented, this is the fandom explanation in a nutshell:

“I’m not drinking that much. Not when Pinch is around. I once drank some punch from the bowl during a party, but it was because earlier that day Apple Bloom tried to sexually harass me with a bunch of apples and I was a bit traumatised. Then she saw me drinking it and I got a reputation.”

Creative swearing:

“By Discord’s kidneys!”

Good old times, part I:

“Wait,” Berry interrupted. “You’re trying to tell me that Vinyl actually was in a college?”

“Yep. Canterlot High, although more high than Canterlot, actually. But she even graduated.”

Good old times, part II:

“You shouldn't have said that. Last time I told somepony to surprise me, I woke up with a changeling in my bed,” Vinyl said. “That was when that sexy princess got married. You know, the one who’s second on my “Ponies I Want To Bang” list.”

“Who is first?” Lyra asked. Octavia shot her a death glare.

A moment of self-reflection:

She [Bon Bon] was probably asking herself some deep, philosophical questions about life, universe and everything, including, but not limited to such things as how to end the world hunger, how prices of gems in the Griffon Empire influenced the demand for lemons in Zebrica, and if the pavement was a good place to revisit her supper.

Good old times, part III:

“No, it wasn’t acid, it was just Lyra and her inexplicable animosity towards bathtubs.”

Lyra and Bon Bon have some issues to solve:

“Bonnie, you do realise that you live only because I haven’t decided if I hate you or Vinyl more right now?”

Good, even older times + Aristocrats:

Octavia looked at the window, her face suddenly becoming pale. In combination with her raven mane it gave an effect similar to the mares from the past, fainting at least twice a day, wearing tight corsets, and dying from tuberculosis at the age of twenty two – best age for an important aristocrat’s daughter to die and still look pretty and young in the coffin. Of course, pretty for those ponies who were wont to attend the funerals to admire the mare’s beauty and weren’t above some physical work with a shovel in the middle of the night, after the bereaved family went home. Lack of scoleciphobia was also a vital trait, as well as courage and ability to create an atmospheric entourage. In fact, some aristocrats of the past made an art of doing weird and ambiguously moral things and calling them ‘eccentric.’ That definitely sounded better that ‘strange’ or ‘weird,’ not to mention ‘queer’ or ‘sick buck’.

Vinyl being romantic:

“After we kissed… After I let you use my flank as a pillow… You do such things to me?”