My five Lighthouses would be areas instead of particular lights:

1. Maine - haven't been to the state.
2. Outer Banks and other lighthouses in North and South Carolina. Again, have not been to either state.
3. Hawaiian lighthouses. Have been there twice, but I wasn't interested in lighthouses either time. Lighthouse collection for me has only happened in the last 10 years.
4. Florida Keys
5. Alaskan lighthouses.