I haven't lived in New England for 30 years, so I don't know if anyone still says "tonic" for soda or pop. When I was a kid "soda" meant only one thing: an ice cream soda. Coke, Pepsi etc. were tonic.
I haven't heard anyone say "tonic" when referring to soda, but then I've only been in MA for about 30 years, so...
I'm sure folks still do it, though!
We also say frappe, which is a milkshake, but with icecream.
The liquor store is a packie (package store). When I went to Michigan recently, I was pretty amused by the "party stores."
ETA: I almost forgot! wicked = very (That was wicked awesome, you are wicked drunk, he's wicked cute!)