Charmy had quite a few priceless quotes in Sonic Heroes.
Let me go! Let me go! I wanna PLAAAAAAAY!
*singsong* Torchies, torchies, where are you!
INCOMPLETE FREAK!
*singsong* Ohhh flower, pretty flower.. show your face and I will sting you!
And of course Vector and Amy resulted in quite a cheesy conversation during their confrontation.
Vector: Excuse me miss, I was wondering if I could ask you something
Amy: If its about a date, it'll hafta wait...
Vector: DATE?! You think this is a joke you little brat?!
Of course nothing compares to leading in Speed Highway and hearing Eggman groan:
TAILS! Wait for meeeeee! ._.
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Yugi2 said:
Issun from Okami jumping out from between a wood sprite's.... [insert word for boobs here]
In Okami, I believe the appropriate term would be "melons". As if Sakuya wasn't bad enough, Issun's dialogue with the high priestess made it quite clear what her most defining feature was... (even Amatseru herself was not immune to it)
Or perhaps that wasn't quite as strange as
possessing the emperor.
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Also, being recently introduced to Touhou I've already found most, if not all, of the dialogue hilarious. Whether its the playful poltergeist sisters, the uncharacteristically whiny Reimu from the second game, Rumia sticking her arms out in an attempt to look cooler by calling to mind the image of the cross (but instead looking like some retarded kid playing "airplane"), and of course, sassy and witty Marisa makes each conversation priceless.
Also worth noting is probably every single ending from the third PC-98 game,
Phantasmagoric of a Dim. Dream, but most notably Marisa's ending.
And of course, Cirno's Math Class. You'll have to study hard if you want to be a genius like Cirno!