The map tool (only for Premium PGC users) is probably the best one to use. It lets you filter down to county level (or country or state, whatever you want). You'll see the Most N/E/S/W and oldest caches in that area.
There are two limitations, however:
1. It's just the listed co-ords, so the cache doesn't have to be the actual most NESW
2. It doesn't let you filter only your finds. It shows if you found one of the caches, but you can't filter NESW/oldest of only your finds.