I didn't know about the two 100kW 104.7s within 80 miles of each other.
Some favorite short spacings of mine:
The 94.5s in Milwaukee (B), Holland (B), and Mt. Pleasant (C1). Milwaukee and Mt. Pleasant are barely spaced legally, and yet they managed to squeeze in a full power 94.5 between the two in Holland/Grand Rapids
The 105.7s in Baltimore and York (both Class B) located less than 50 miles from each other.
The 96.1s in Holland (B) and Bay City (C0)
106.9 in Milwaukee being shoehorned in between a 106.9 in Muskegon and a 106.7 north of Chicago
Detroit and Cleveland sharing several frequencies despite being less than 100 miles from each other
97.9 in Grand Rapids being shoehorned in between Chicago and Detroit