Well, I've said it before, but I'll mention it here.

My biggest, BIGGEST pet peeve, that makes we wanna spit nails, is city maps with all buildings as separate entities. Think of it as the following:

O O O O O

The O's represent buildings and they all are separate. Like an entire city built on the suburb style. No city in history has looked like that. The look like:

OOOOO OOO O OO OOO

With the buildings in clusters, sharing common walls, etc.

So, as said, I have seen a great many beautiful city maps (and a lot of them here in this forum), and then they lose that sense of verisimilitude (The quality of appearing to be true or real. / Something that has the appearance of being true or real.)

And that is a crying shame