They’re in most of the western states, going as far back east as Missouri, Arkansas, Texas and Oklahoma. I’ll visit one when on the road for a dependable breakfast with slightly more charm than Denny’s but that’s about it.
Spud only has 2 locations so doesn’t meet the definition of chain as posted in the OP.
It’s pretty famous (locally). I used to live in the Juanita area of Kirkland for a number of years, and we’d go to Spud now and then. I really loved ordering zebra clams* (they are ENORMOUS) and garlic aioli to dip it in. Spud is weird; they charge you for everything. You want ketchup with your fries? You gotta pay for that. But when you buy the ketchup (for a relatively cheap price) you get a really big container of it, not some tiny packet. For example, when I would order the garlic aioli, I got enough of the sauce for all of my clams and my fries. Really nice place if you like fried seafood. That’s also the first place I ever tried fried zucchini, it’s delicious too.
* I don’t know why they called them “zebra clams”. When you ordered clam strips, they came in “regular clams” and “zebra clams”, and the latter were huge. I looked up to see what a zebra clam was, and there doesn’t seem to be such a thing. Zebra mussels exist, but they are tiny and don’t taste very good. I don’t know what I was eating but whatever it was, it was delicious.
My wife is from Buffalo, and I really enjoy local hot dog stand Ted’s, with a number of local locations, and one outpost in Phoenix. I dare say, as a Chicagoan – and I may lose my city citizenship for this – it may very well be my favorite hot dog. Natural casing, as I like 'em (skinless hot dogs are eliminated from being my favorite, though I will eat them), grilled, pork-beef mix. I have to say, all-beef hot dogs are a bit over-rated, especially when grilled. I find a pork-beef blend makes for a better grilled hot dog, although I prefer all beef for steamed/boiled dogs (like typical Chicago dogs.)
And there is also Anderson’s Frozen Custard, selling roast beef (on weck) sandwiches that Arby’s only dreams of serving. Now there is better beef-on-weck in Buffalo, but for a quick fast food-ish type of stop, Anderson’s does hit the spot.
I just wish there was decent roast beef on weck in the midwest. I fell in love with that sandwich during a weeklong visit to Buffalo back in 2010.
City Barbecue started out near Columbus, Ohio and we ate there on many occasions when living in the area. A few years back they decided to expand nationally and now have 50+ restaurants in the Midwest and Southeast (including a Kentucky location near us). I’ve been anticipating a drop-off in the quality of the food but it’s stayed good. Worthy brisket, ribs and sides.
Pappadeaux Seafood Kitchen was a haunt in our southeast Texas days. Their outlets are mostly in Texas but have spread to a few other states. Unfortunately we have to drive to New Springdale, Ohio (near Cincinnati) to get our gumbo and crawfish fix these days. Hoping to convince them to open a restaurant in central Kentucky.*
If you fly into or through Dallas or IAH in Houston there are Pappadeaux locations in the terminals.
*I’d settle for Legal Seafood, but it’s more expensive and the menu’s not as varied or crawfish-friendly.
Hmm… you’ve inspired me to look up what local offerings there are for beef-on-weck, and this place looks pretty good in Chicago, open for lunch F-Sa-Su: The Little Pickle. I don’t feel like clogging up the thread with a picture of their beef, but it looks pretty good to me. I’ll have to do some research this weekend. 
El Ranchero Mexican Grill is a fantastic Mexican restaurant with three locations-- Franklin, VA (the only one I’ve been to, about 8 minutes away from me), Emporia, VA, and Murfreesboro, NC. They usually have soccer from the Hispanic channels playing on television. I get the Three Amigos, which has chicken, shrimp, scallops, zucchini, and onions, and I add broccoli a la carte, on a bed of rice with cheese. Mm-mm. Delicious. And of course, the tortilla chips come with a side of salsa and the famous Virginia white sauce.
Atlanta has a couple of local Tex-Mex chains. Moe’s is good for a basic, inexpensive burritos-quesadillas-tacos menu, but for really good burritos and quesadillas, the cognoscenti go to Bell Street Burritos . Only three locations, so just barely qualifies for the OP’s premise. They make the best tortilla chips I’ve ever put in my mouth - light, crunchy, flavorful without being greasy or heavy.
The Varsity is pretty well-known, and just about every Atlantan has eaten there once. The first one was opened in 1928 by a Georgia Tech dropout, who was told he’d never succeed in life. So he moved across the street from his erstwhile alma mater and opened up a diner. Burgers, fries onion rings and hot dogs - they’re especially known for their fried pies and Varsity oranges, sort of like an orange milkshake. They used to have carhops, one of whom was a local high school student named Nipsy Russell.
Never eaten at Lotaburger, but the name is familiar to any fan of Tony Hillerman’s Navajo police mysteries. Jim Chee eats there frequently.
Cook Out has expanded to Atlanta, which is a good thing, as it’s the only place in the city to get Eastern North Carolina-style barbecue.
I used to prefer Skipper’s over Ivar’s, but the one in Olympia closed down close to 10 years ago now and I’m not sure if the chain even exists anymore. They had a basket that came with a fish filet, fried shrimp, clam strips, fries, coleslaw, and chowder for about $10 that was worth every penny.
It does, they’re all over although there might be a lot fewer than there used to be.
There’s one in Silverdale that has been around at least since I was a teen.
I’ve never been a huge fan though, I just never thought it tasted great. Everyone’s tastes are different of course.
Tucson has Eegee’s. Sub shops most famous for its frozen drinks - kind of like a frozen slurpee -called an eegee. I think it’s over rated.
There’s a sandwich chain called Baggins.
Interesting! I’m not big on mysteries, but I took a moment to read through the author’s wikipedia entry. Sounds like he found his forever home in New Mexico, the way John Denver may not have been a native but fully made Colorado a home.
As for Blake’s, like a lot of the best burger joints and chains, it’s been there forever, as it’s celebrating 70 years of business now. Apparently it’s even in Breaking Bad, upping the shows Albuquerque cred! But roughly 14 years of living in New Mexico made it a big part of the taste of home for me, and I regret the closest one is 260 miles away.
I hope they sell their sandwich bread in frozen loafs called “fro-dough”.
There was (may still be) a Skipper’s conveniently located next to the lineup for the Edmunds ferry. I tried it once and wasn’t impressed, especially since Grub Hut was located on the other side of the crossing in Kingston.
Tempe actually, next town over. I suspect so they have an excuse to winter over here. Really good dogs though, I’m glad we have it.
Cornish Pasty Co. Three locations for the longest time here in Phoenix-metro area, then expanding to nine in the past year.
Pasties are virtually their whole offering aside from some salads, but they have a lot of varieties.
“In the Northeast (New England, New York area) we have Friendly’s”.
We have a few Friendly’s left on Long Island, and they were my go-to for first date casual dining (I think 5 dates at 5 different Friendly’s locations, and a.) yes I usually did get second dates afterwards and b.) apparently I was following Red Pilled advice (among other “rules”, don’t spurge on a first date, keep it casual and low-cost) before Morpheus opened his hands to unveil the trope setter.
Anyway, moving back to chains…for a local chain I was going to suggest Nathan’s Famous, but turns out they have locations in many states including Florida, Texas and Nevada, so that doesn’t count anymore (in fact they’ve even closed some Nathan’s on LI, replacing one with a Chic-Fil-A, which IMO doesn’t taste all that great). Cookie’s Steak Pub is long gone, and frankly pretty much all the chains we do have come from out of state (and there are lots of chains we don’t have that other states have like Jack’s, Del Taco, Carl Junior’s, etc.). OK, taking the rather small unknown village to the west of us called New York City, well you have the rather bizarre chains of pizzerias called Rays (fantastic name BTW), or rather since that closed, either Original Rays , or Ray’s Famous (which I believe are still chains). I ate at several of those chains when I was in Manhattan a lot during the turn of the century, and quite frankly they all kinda sucked. There must be some food chain pretty much located to New York…I got it, Bagel Boss - their bagels are pretty decent…
I guess Black Bear ain’t anything like ‘regional’. Did not know that. Well now I do, I guess.
On a similar note to Black Bear, there’s Shari’s, which is based out of Oregon and operates mainly in OR and WA, with a handful of locations in northern CA and ID and one in Wyoming. Around here they have the reputation of being “Denny’s for old people”, and they feature a large selection of pies which can be purchased by the slice or whole to go. Their restaurants are housed in distinctive hexagonal buildings with the kitchen in the center.
When I was a kid, the fried mushrooms were something to get excited for. I liked the chicken just fine but it was the mushrooms that were “Oohh… Browns!”. The last time I had them (I was unaware the chain still existed) was a good 15 years ago and they were rather disappointing. But that could have just been the location (since closed), a bad night in the kitchen or simply failing to recapture my youth.
Out in the Chicago southwest/west suburbs is a small chain of Beef & Gyro style strip mall joints called Doggie Diner. While the hot dogs are good enough, their beef is probably the best I’ve had in the immediate area. They also have the distinction of serving Green River soda on tap which is always fun and giving you more fries than anyone can eat. When I was a kid, our cat had a particular love for their fries, likely cooked in beef fat, and my mom would get the cat its own small dish to chow down on.
They used to have five or six locations but, looking now, they are down to three and I think one is actually separately owned (it’s a family business so I think the sister owns two and the brother owns one). Another is closed, one was sold to a separate party who renamed it and I might be imagining the last or else it’s closed/sold as well.
When I was in college they were a local chain with maybe a dozen locations around the Greensboro and Raleigh areas. Now they have over 250 restaurants in 10 states. Yeah, they’re really too big now to qualify for this thread, but I guess that horse has left the barn since we’re already talking about them.
And on that note, are there any New Mexicans here who can tell us what Twisters is like? I admit, I only know them because one of their restaurants served as the Los Pollos Hernamos set in Breaking Bad and Better Call Saul. But it looks like they’ve got several locations around New Mexico and Colorado.
Adalberto’s is another Sacramento one I thought of. Their web site lists 10 locations, but I know there’s one in Folsom that isn’t listed, so I don’t think they keep their site up to date. I’ve only tried them once; it was decent, but nothing special compared to other Mexican places in the area.