There was this one mom and pop burger joint that had the simplest, most basic, super greasiest burgers but to this day they were the best burgers I’ve ever tasted. The place was tucked away in an alley and it was one of those “you have to be a local to even know this exists” places.
Also, having moved from a smaller town to a bigger city, I miss how close everything and everyone was. You wanted to go see someone, or go do something, it was always just a walk away instead of having to deal with all the hullabaloo of traffic and bus lines and yada yada.
US -> Japan. Mostly, I miss family. I have basically no love for the area in which I grew up nor contact with anyone there (half my family never lived there, the other half moved to another state).
I do miss some foods that are hard to find or very expensive here. Things like PC parts are (or at least were) much cheaper in the US since it was generally a niche hobby device outside of business use here until quite recently.