Many of Marisa's jokes, but her conversation with Reimu in chapter 14 takes the cake. It's about a card game, and somehow she manages to sneak not-so-veiled sexual innuendos in. Reimu's snarky retorts are no less funny.
And Marisa really seems to follow close in her master's footsteps, hearing what she says to Reimu in chapter 41:
Mima:Such a scar, especially one earned on the field of battle, might be to your advantage. Certainly it would discourage people from picking fights, and I hear that they're quite fashionable in many circles. It'll make you a hit with the ladies, that much is certain. Reimu:"Mima, I'm a girl, remember? Mima:So? That's never stopped Marisa. Reimu:That's her! I'm not into girls, okay? Mima:Or boys, for that matter. Or most anyone. Goodness, child. No wonder you're always so crabby. The sexual frustration must be- Reimu:Shut up already and fix my godsdamned face, all right?
Earlier in Chapter 36 and the same Chapter 41, Rin Satsuki starts to make some of the weaker characters literally be a case of Bring Me My Brown Pants. Yeah, that kind of stuff happens too, and Nazrin's is Actually Pretty Funny.
Nazrin: "Heya, cap'n?"
Nazrin: "Permission to crap myself?"
Nazrin: "Uh, what if I already did?"
Murasa: "Clean it up, then."
This bit on chapter 21, consider how reunions of the Ringleaders went, the tengu and kappa consider Kanako's takeover a blessing:
"At the far end of the Tengu Village was the mansion of Boss Tenma, the Tengu leader. Before Kanako's arrival, he and his counterpart among the Kappa had sat among the Ringleaders in representation of their respective societies. However, once Kanako had established herself as the goddess of the Youkai Mountain, it was decided that she would represent both peoples. Neither leader had protested the decision, and reportedly Tenma had immediately declared an entire week of drinking and partying in celebration."
Mima using country music and Soulja Boy to null Satori's mind-reading powers.
Mima: "How does one superman a hoe? Are they talking about the gardening tool? How does one superman it?"
The Kourindou intermission in the end of Chapter 47. To explain it, Rinnosuke is wearing nothing but a towel (a reference to the Memetic Mutation of the fundoshi) as he explains about the lack of common sense in Gensokyo and forces an annoyed Marisa to give him a piggyback.
Among the many occult books in his library, like The Necronomicon and The King in Yellow, Dream of the Endless also owns a copy of The Junior Woodchucks' Manual. What makes it even funnier is how Yukari reacts, thinking that it's probably one of the most fearsome occult tomes in existence.
And, well... it could be. Who knows if they have a section on Outer Gods?
In Rhapsody of Subconscious Desire
When Mokou reaches Kaguya's mind and finds herself in Kaguya's ideal, modernized Gensokyo, a random commoner recognizes her, so she deduces that, being Kaguya's ideal world, she would be a wanted criminal. Nope, worse. She's an Idol Singer.