Have you tried Woodman's in Essex? Their fried clams are outstanding...fried in pure lard and worth every calorie and clogged artery. Also, good chowder and lobsters...you choose 'em, they cook 'em.
The lines are long and it is a little pricey, but not Summer Shack pricey. No Jasper sightings but still terrific.
re: Fish heads and rice
obviously youd be better off in the north shore or Maine. That wasnt my point. if you worked all day in downtown boston or cambridge or somerville or arlington or anywhere within ten miles, its 7 pm on a tuesday and you want that kind of food, then summer shack is a good bet, even if its overpriced.
and i wouldnt go to legal seafood even with my boss' credit card if i had another option