I hear good things about White Castle, just never been to a state where any are located...
however we do have Carls Jr (odd trivia, Carls Jr started as a hot dog cart in LA but there's no hotdogs on their menu) and most of the "white castle" states don't so we do have some things going for us..
I get dunkin donuts coffee for a drip machine, decent coffee. but I don't see anything special about it, I believe Pao's donut shop in Tacoma was one of those dunkin donuts locations in the 80s that flopped, and Pao's makes outstanding donuts, so we're not really in a bind for good junk food here...
If you want to sample White Castle, the cheeseburger ones found in some stores like Walmart in the freezer section do actully come out tasting near exactly what you get at the franchise stores.
For me, I love the steamed roll, the onion and the more coarse ground beef taste/texture combo.
I got to re-experience White Castle about 3-4 years ago when my job before this one had me travelling all over, and i ended up in Northern Kentucky again. I was managing a crew of about 18 Labor Ready guys, and they would all dissapear to WC during lunch breaks so i tagged along. 30 years since I had a WC burger till then. Just as good IMHO.
When I lived on the east coast I never heard of Carls Jr, but back there we had Hardees - my understanding is they are owned by the same parent. Might not have been true from the beginning, but it was then as best i can tell.
Regardless, regional influence will make or break any franchise. Dunkin makes good coffee, but its not what the palete of the PNW wants. Back east, if the coffee was strong and did not taste like crap, it was a good coffee. It woke you up and got you ready for the day. That was good enough.
My younger days there I was a bass player for a darn good local band. We had a span of three states we would play. One of my most fondest points in that was the "recovery" of a night playing somewhere. See,we had to roadie ourselves. So half a day getting set up the sound system, getting a soundcheck done, doing 4 - 45 minute sets, tearing it all down and packed on the traliers, and starting that 3 AM hangover from what beer you drank... stopping into a Waffle House for a bite to eat before you passed out in the roach motel you booked was a highlight.
Endless coffee, greasy food, but god damn, was it a comfort. Hashbrowns, doubled, covered, and smothered, with a side of Bacon, no, make that two sides of Bacon...
At the time, that dull boring coffee was just what was needed, no "poofters" coffee was needed.