Back in the 70’s I ate at a drugstore lunch counter. Food was plain, basic, cheap. Grilled sandwiches, soup, fries, with maybe cake or icecream as a dessert.
In Madison , Wisconsin , we had Rennebohms that had lunch counters and restaurants. Breakfast was cheap.
At Woolworth’s and a pharmacy called Huerbingers. When I spent the night with my grandmother, we would take a cab to downtown Glenview and get something at Huerbingers. I haven’t thought about that in years.
Frequently ate at the counter at Montgomery Ward and Walgreen’s. It was basic stuff like meatloaf and mashed potatoes. I remember that if you ordered a burger it was accompanied by potato chips, not fries.
At least twice last year. Once at Wholefoods and once at Selfridge’s in London.
My Kmart growing up in Great Falls Montana had a cafeteria inside of it with a counter. It was always really special to get to eat there. I was sad when it was eventually removed.
I believe Bakersfield has an old Woolworths that is now an antique mall. The lunch counter is still in operation. I ate there once.
KDW in Berlin has a whole floor with counters and then a whole floor with a cafeteria. 
Our local K-Mart in the 70’s-80’s had their own restaurant with counter, and it was actually decent for a while, but went downhill.
The now defunct Famous-Barr (now Macy’s) had several outlets locally, and one had a small “cafe” deli-type restaurant (no counter, though) with good soups and sandwiches. I had my first Reuben there, and they always had an awesome French Onion Soup (served in an insanely hot crockery bowl with cheese on top), in addition to the soup of the day.
I remember eating at about six different ones- Ward’s, J. C. Penney, Woolworth’s, Arlan’s, K-Mart, Ayre-Way (if you know the last one, you know where I grew up).
The big old department stores downtown had lunch rooms or tea rooms, serving very good food by waitresses who had worked there forever. i remember I ordered broiled fish and mashed potatoes, the fish was cooked to a fare-thee-well and I didn’t eat it. So I got a bit of heat from the waitress for that!..Later, there was an excellent deli doing booming business at lunch time, in Sibley’s - you could get a pretty big container of ordinary lettuce salad for 50 cents, and order hard rolls, lunch meat, or cooked chicken pieces. … now, at what is now K-Mart, it is within living memory that I recall a luncheon nook where they served popcorn, ornge drink, hot dogs, and mysterious sandwiches prepared elsewhere and brought in…“egg salad”, “ham and cheese”…the kind of thing you would get at a thruway restaurant, or out of a vending machine in the basement of a used car parts store.
We recently grabbed a bite to eat at one of those old-timey drugstore lunch counters where you can get a soda-fountain egg cream while waiting for your tuna melt.
Turns out that egg creams taste awful.
You don’t no nuffin! And you drink at horrible sodee fountains!
Once or twice I ate at a Woolworth’s when I was a kid. Probably had a hamburger.
The local drug store had a counter; I probably got a sundae or two there. Later, my father bought the building; I loved going behind the counter and seeing the equipment – the seltzer spigot, for instance.
Yes, also a Kresge’s
The diner in my hometown served phosphates - cherry and lime. Yum. I actually acquired some acid phosphate recently so I can make my own, since the diner finally closed about 10 years ago.
We ate at the Woolworth lunch counter all the time. My mom worked at the store and my aunt worked at the restaurant, so we’d go in when she was working and sit in her section. I’d always order a tomato juice and if my mom had enough money a plate of bacon.
I remember I my Mom took me to the restaurant at Hudson’s Department store in Detroit, in the late 60s/early 70s. There was a kid’s meal of some kind, that had a picture of, I think, an elephant to color, and came with a banana for dessert. I think the main meal was probably a hotdog.
They’ve been brought back! 
(sorry, the link goes to an article preceded by an auto-play news clip video)
Oh, as for me, I’ve eaten at the KMart cafeteria at least once, maybe more before my memory. I don’t remember anything about the food. KMart moved out a long time ago, and the cafeteria was gone before that. The store is now a Burlington Coat Factory.
One year in college in Madison, WI (early 80’s) I had a very early morning class and then nothing for the rest of the day. On the way home after class, I would stop by the Rennebohm’s pharmacy on the Capitol Square and get two eggs, toast, bacon, and hashbrowns for $1.99, then I’d go home and go back to sleep.
The Woolworth lunch counter was a series of U-shaped indentations to get the most usage out of the space. That was a lot more fun to sit at than the Neisner’s across the street, which had an ordinary, if very long, straight counter on the main floor. However, the Neisner’s had a cafeteria in the basement which set out zillions of foods and allowed you to assemble your own trayful. That was by far my favorite as a kid.
Woolworth’s or W.T. Grants. Not sure if Grants had a lunch counter. They were both in the same shopping center. At the time there was only 1 small chain restaurant in my area before McDonalds came in.