Shhhhhssssh Johnson Cove is one of my favorite places to drop my anchor, and never very populated !
Winter Harbor is also great and big enough for tubing or sking, and out of the rough water of the Broads.
Chesnut Cove can be nice, near the entrance of Alton Bay. Great West view of the Broads. Never busy there.
Around Barndoor Is, near Wolfeboro harbor is nice to anchor, and has places to snorkle. Watch the rocks !
Last, one of my favorites spots to anchor is on the south side of Birch and Steamboat islands, facing Jolly Is. Watch out though for rocks close to shore, they're the size of Volkswagons !