Hanyuu and Yuki's encounter in the bath. Each believes the other to have unfriendly intentions towards Kyon (who they're both playing "invisible spirit guardian" for the moment) and nearly come to blows... and then Kyon abruptly stands up and starts looking for a towel. Both girls immediately stop fighting and just STARE for a minute or two.
Hanyuu: We have just shared a wonderful experience. We should use this opportunity to become friends.
In Chapter 18 Mikuru was starting to complain to Haruhi because she was talking with Tsuruya while leaving her in the dark, until Haruhi shows her a picture of Kyon wearing an apron.
Mikuru: That's not fair! What do you think- *squee*
"Well... 'future me' is a bit arrogant and constantly thinks that he can talk down to me just because he's been through whatever," Kyon sighed. "While past me is in fact incompetent, and I'd never go back to save him if he hadn't messed up in the first place. Present me, naturally, is just perfect."
"Crazy Asakura bits". 'nuff said.
Tsuruya's line after the aforementioned crazy Asakura bits get turned into the PDA, Skynet is priceless.
Is that the end of the world in your pockets, or are you just happy to see us?
After Yuki hugs Kyon to buy Haruhi time to mess with Kyon's PDA:
Haruhi: Er, er, good work. Um, more emotion next time, Yuki, and then we'll have that sequel down solidly! Yuki: Good. Haruhi: That means you can let go! Yuki:Understood. Haruhi: That means let go!
Koizumi's reactions to the sensations he's receiving through his link with Haruhi in Chapter 29, while Haruhi and Kyon are making out in the stairwell, are nothing short of priceless. Zoning out randomly, acting hilariously flustered, and finally delivering this gem of a line under his breath when the pair stops:
In Chapter 35, Kyon calls Yuki by her given name for the first time in front of all brigade members, cueing her first unmistakable Luminescent Blush. The event even warranted interference from future to ensure the moment was properly recorded.
Haruhi (to Kyon): Did you, or did you not just see the most amazing explosion of moe within this room ever just now?
In Chapter 40, Haruhi's sheer incredulity at Kyon's sincere attempts to defuse an impending Marry Them All scenario is nothing short of hilarious.
Haruhi: And, come to think of it ... you're a guy! What is wrong with you that you're trying to get out of a relationship with five attractive women?
Koizumi shows himself to be a Rena-sensei fanboy (Brave Detective Sasha Fan-club, member #24601) when Kyon reveals that she's his aunt, and Squees over the prospect of meeting her.
"Kyon," Koizumi said with unexpected heat in his voice, "I don't know that I've ever asked for much as a personal favor - but please let me meet your aunt!"
"I understand that human males experience a lot of urges like that at Kyon-kun and Koizumi-kun's age," the figure replied, giving a solemn nod. "So it makes perfect sense that they would work together to get rid of them instead of spending time trying to get females to help!"
Chapter 54 gave us Tanaka Taro, the thug with ambition and a completely forgettable name. Let us not forget his final line in the chapter:
He was nothing, if not an ambitious man. From dockworker to management ... he would follow this path and truly achieve greatness in the shipping industry!
In chapter 56, Taniguchi's accidentally makes Sakanaka sad whilst finding out about her crush of Kunikida, leading to him resorting to "Hey look! It's a convenient change of subject!", whilst pointing out the window. Made even better by the fact he points directly at Kunikida.
Chapter 57 has Kuyou attempting to bake cookies the size of a planet, while using a shadow-song version of the sun as an oven.
Ryouko: "Sorry, we need to work on that communication gap; it looks like you're trying to work with a ball of sugar that's twenty times as far across as the Earth is wide."
During the second trip to Hinamizawa in Chapter 59, Kyon and most of the girls in the Brigade teleported to Yuki's Pocket Dimension for some training. Hanyuu instantly assumed they went somewhere to do "naughty things" and ran off to inform Rika... only to be stopped by Kuyou buying off her silencewith cookies. Funnily enough, the "bribing" part only happened in Hanyuu's head as Kuyou missed most of the implications and only wanted to share some of her cookies with her.
Hanyuu: "I'm sorry, I'm sorry, I'm sorry— But— But I have to explain that Kyon-kun was alone with all those girls, it is so!" *moments later* Hanyuu: "Teenagers will be teenagers, there's no sense in spoiling their fun, is there?"
In Chapter 61, The Reveal that the protagonists' harem antics are going to be novelized in-universe.By Rena. Bless you, Nonoko.
Rena: You know, I've been thinking about my next book series? It's about a young man who's chosen by a number of different kinds of magical girls— So a ninja girl* (Yuki), a traditional magical girl* (Haruhi), a princess from a different dimension* (Kanae), a fairy* (Kuyou or Ryouko, probably both)....
In chapter 62, Sasaki faints very politely.
"So ... you're okay? You understand all this now?"
"I think so. But it strikes me that it would be a very good time to faint right now, if it's not too much trouble."