Wow, what a great selecton of quotes! Nice you mentioned Touche, and yeah, Henri is hillarious
Narrator in Al Emmo is also producing many one-liners.
Some more:
I'really wish i could help you but i'm just a clueless old fool - Kalypso in Simon the Sorcerer 2, and the whole dialog is hillarious
I've had some bad days since I started work as a private investigator. But I've never woken up dead before. - Lewton in Discworld Noir which is full of great quotes
¡Madre de Dios! ¡Es el Pollo Diablo! - Captain Blondebeard, The Curse of Monkey Island
and two from Escape from Monkey Island:
Guybrush in a deep, manly voice -
Why hello there, Brittany.
this cracks me up, i think they used completely different actor, check here -
http://www.youtube.com/watch?v=F_t_UA_neeY&t=4m34s
and Freddie, the Stickmaker -
If I wasn't a peaceable sort, I'd have a mind to whack that gentleman upside the head with one of my walking sticks. And I wouldn't stop whacking, until his brains leaked all over my rustic, hand-polished, hardwood floor. A'yup.