Two regional favorites:
Moxie
Cheerwine
True story - The wife and I road tripped from Connecticut to Georgia about 15 years ago, and when we got south of the Mason Dixon line she starts talking about Chick Fil-A, which t the time was not around in the Northeast.
We stop for lunch at a Chick Fil-A in some small town off the highway in North Carolina. I order a chicken sandwich meal with waffle fries.
Now the girl behind the counter doesn't actually ask what I would like to drink, she spoke a sentence that sounded to my New York-born ears something like:
"Dijoo wahncherWINE witthat?"
Me: "I'm sorry, I didn't quite get that, can you say that again?"
Server (trying not to sound annoyed): "Didjoo wahncherwine witthat?"
Wife (making no effort at all not to sound annoyed): "She's asking if you want Cheerwine with your lunch"
Me: "Um, what is Cheerwine? We still have 300 miles to go."
Wife (sharing eye-roll with server): "It's like a cherry soda. (To the server) - "Yes, he'll have Cheerwine."