I’ll start:
“She can’t count too good, but she shore is purty.”
Cowboy Sid, referring to Sheila The Wonder Horse on a Krystal commercial.
What’s Krystal?
We’re at least some an international board, and definitely an all-50-US-states board. A lot more commercial stuff is regional than people who never leave their home region realize. I’ve lived in 6 states spread across our country and I’ve never heard of a product or store called just “Krystal”.
My turn:
If you’re from SoCal, and only if you’re from SoCal, there’s “I’m Cal Worthington and this is my dog Spot.” Hint: Spot was many different kinds of critter, but never, and I mean never, a dog. Bonus points for anyone who can say which competing dealership this was a direct dig at. 
“It’s stuck, Helen.” “Cold again, too.”
“Dogs LOVE trucks!”
“Gentlemen Prefer Blondes”.
Something I recall almost entirely because I saw it a lot in magazines as a young kid (which would put in sometime in the 1970s) and was really offended by the slogan because I mistook it as an order. I thought it was trying to command me to prefer blondes, which I found obnoxious and presumptuous.
The White Castle of the South. (The founder visited a WC on a trip to Chicago, and copied the idea when the went back home to Tennessee.) Not a single location north of the Ohio River.
Thank you. Here in FL there are two Krystals, both in greater Orlando. I did live in White Castle country for 20 years.
Water closet?
This line is probably not so obscure. It is from a commercial I used to see often that I found annoying, but I can’t remember the exact commercial to link it. I expect it will be non-obscute enough that someone will be able to find it:
“Zorb it? Hehehehehehehehehe!”
That’s a joke from Jack Paar. But that’s important right now.
During WW2 Lucky Strike cigarettes were in green packages until dye became scarce, so they changed to white with the slogan:
“Lucky Strike green has gone to war”
“I always wanted to work on a transmission”
Sorry; it’s a mini-burger joint, a southern version of White Castle.
Seems like @Kent_Clark provided plenty of context there. Or did you skip the first part of the paragraph? 
Crazy Eddie!! His prices are insane!!!
Crazy Eddie being a regional chain of home electronics stores with a frenetic spokesperson. I haven’t heard it in over 40 years but it immediately popped in my head reading the thread title.
I suspect most of us could think of a local/regional store with a “frenetic spokesperson.” The one that sprang to my mind was the furniture store “Where you always get a free onion!”
Does it come with belt loops?
Here’s one from the UK that overseas fans of The Bonzo Dog Doodah Band might recognise as the source for one of their lines:
“This is luxury you can afford - by CYRIL LORD!”
(Cheap carpets, long since gone out of business)
I was curious who invented the whole frenetic spokesperson thing.
The best I can come up with this guy.
Interestingly, Crazy Eddie and Cal Worthington are both mentioned in the article as examples of people who copied him.