In the US. My home airport, SEA, seems top heavy with lounges for its size.
-BA lounge
-skyclub
-centurion
-united
-2 Club at SEA
-3 AS lounges
-delta is going to build another lounge at the end of A gates.
-3 priority pass restaurants (if you want to count those)

9 current lounges
10 including the yet to be built skyclub
13 if you include restaurants.