@CountingDown there is still at least one Krystal’s in Memphis, where I grew up. When I was a kid, I really liked their little hamburgers.
One restaurant I haven’t seen mentioned here that I have fond memories of was Shakey’s Pizza. We used to go there quite often to listen to the live music, although I don’t remember the pizza being anything special. In fact, we had a family friend who played banjo and often used to perform there. There used to be one close to where I live now but it closed several years ago. When my son was young we had several soccer parties there. Are there still any open in the U.S.?