My top 5...

1)Nobska, MA
(I remember as a kid riding out to Woods Hole with my aunt and uncle who lived in Falmouth on Cape Cod. It was nighttime and the road had the ocean on the left and a bluff on the right. The car turned a bend and I saw the rotating light beaming out over the road and the ocean and then the lighthouse at the top of the bluff. Been hooked ever since!)
2)Owl's Head, ME
(Perhaps the most lovely spot for a lighthouse anywhere!)
3)Chatham, MA
(Whenever I need a lighthouse fix I take the short drive out to Chatham)
4)Palmer Island, MA
(From my home town of New Bedford, MA and one of the very first lighthouses from my childhood. So glad I was able to convince Harry to make this one!)
5)Marblehead, OH
(Saw it not long after a repainting a few years ago. Fell in love with it right away).