Best not to eat "seafood" in New England. Shellfish, yes, but not fish. Never, ever, under most circumstances eat fish in New England unless you caught it yourself, or maybe (just maybe) in a very high end restaurant and if it's "atlantic dayboat" fish. Boats go out for 5 days at a time, because really there's no fish near here, it's all gone. There are clams, though!
Summer Shack has as decent fried clams as you can find close to the city, if you can't make the drive up to Route 135 to get better ones. Their lobster is among the best cooked you can get in MA, but not as good as in Maine. If you go there don't be tempted to get fish, nor should you even think of getting your lobster prepared any other way than just steamed. The steamer clams are good also. If you don't want to get lobster or clams, don't go there. Have Indian Pudding for dessert if you do go, it's another good local treat and they do it better than all the other remaining local places in Massachusetts.
If you go to Molana (recommended above), decor and service is standard Persian restaurant style - but food is good. I go there a lot, the best thing they do is "Chicken Soltani" if you order it with "shirin polo" which is basmati rice with sweet orange peel / carrots rather than plain basmati. Definitely try the saffron ice cream for dessert. If you go there more than once, try the Ghormeh Sabzi. Around the corner from there near Watertown Square is a burger place called Wild Willy's, and I also go there often - kinda hoaky family style place, but three choices of locally sourced meat, artisanal cheddar cheese, toasted & buttered bun. If you go there, keep it plain and simple - med rare with nothing but cheddar is my call, it can compete with NYC's Burger Joint.