What are you looking for that your can’t find in either the Rand McNally Road Atlas or in the Key Map Book for a given city?
Rand McNally used to sell a six county map that I would buy every 2 or 3 years as I wore them out with use. The last year they made it (Chicagoland) was in 2006.
See my #7. I have the Rand McNally Road Atlas and many state maps, most issued by said states. But, they are quite limited, and, often what detail is there is getting hard for my old eyes to read (even with new glasses, and esp. if the lighting is poor.)
A state map of Ohio, for example, or an atlas, is not going to show me where the rural driveway I’m looking for is at, local landmarks / terrain, etc.