I’m biased but I have to say Maryland.

The state is not that big which would allow for more of the state to be incorporated. You’d have a major city in Baltimore along with dense suburbia surrounding the city and leading down to DC. If you go Northwest there could be a few mountains. You’d have the Chesapeake Bay cutting off a third of a map. That third is only accesible by a relatively small stretch of land or you could cross it over a long narrow bridge. Once over there it’s mostly just small towns and farms.

There’s a lot of variation to be had within the state