Let’s try to stick to standard issue supermarkets. That is, no specialty/convenience stores, wet/dry markets, etc.
Ones that just came to mind–
Orkideh in Kashan, Iran: pistachio butter grinders
Soriana in Matamoros, Mexico: smoking (tatemando) peppers while you shop
on that note,
El Corte Inglés in Spain: they’re a department store chain, but the ones with supermarkets will cook seafood for you. To wit, damn those were good percebes.
Gourmet Market in Bangkok: Thai fruit and juices, prepared meals, and imported snacks from around Northeast Asia
City Market in Mexico City/Puebla: white chocolate almond butter grinders, plus heaps of spice blends
generic supermarkets in Japan: the roasted sweet potato stalls by the entrances, the eat-in sections, the range of prepared foods
n.b. I posited this in reddit too, but also appreciate the food lover mantra of Hungry Onion.
KaDeWe in Berlin — although technically not a supermarket. You can find pretty much anything there, especially if you have the euros to spend.
Harters
(John Hartley - a culinary patriot, cooking and eating in northwest England)
3
Carrefour in Calais. Always a stop to stock up before getting the ferry. I remember once buying a whole string of smoked garlic - so strong a smell of the smoke we had to keep it in the garage. And, cheeses from the Pas de Calais and Nord regions.
Oh, and a jar of the local delicacy from this region of France and neighbouring Belgium. Sold as “pot jevleesch” in the former and “potje vleesch” in the Dutch speaking part of the latter.
My local indie supermarket, Berkeley Bowl West. An organic produce section that’s as big as most supermarkets’ entire produce section, and a non-organic section that’s three times as big. Butcher counter, seafood counter. Bulk grains, nuts, and spices. Berries at 1/3 the price in the Bargains room. Hot bar, olive bar.
Do a Google search on the name, and click on Images to see what I’m raving about.