So much to say.....
I belong to Tedesco, so I am a little biased towards it....but I have to agree that Essex is quite possibly my favorite course I have ever played, at least on this side of the Atlantic. I have played Stow Acres North and thought it was a little scruffy for a former USPL tourney, though i've heard they have done some work to remedy that. Of the others mentioned, I've played Myopia, Crumpin-Fox, Shaker Hills. I've been trying to get on sandy burr for two year, but the tee times fill up so fast i've had little success. All of the private clubs mentioned i've yet to see, but am very interested in finding ways to do so.
For my several gems that i would mention, they would include Beverly Golf & Tennis Club (Emmet & Tull, used to be United Shoe CC), Gannon Golf Club (a WPA course built during the depression that suffers a bit like George Wright), Bass Rocks in gloucester (H.C. Leeds in about 1890, rock outcroppings in some fairways, great views of ocean, though somewhat tainted by three new holes that replaced three others that played across roads that were much better), and Bass River on the cape, a Ross course with an interesting split of 34-38 that is generally flat and uninteresting, but has several all-world holes (11).