I hate to be a killjoy, but what if it's NOT a "shack"? How about a hole? A dump?
I just want good seafood and I don't care if it is a tent or lean-to! I just love to find good finds, when it comes to things fishy.
What does shack mean, anyway? Should I post this on "not about food"? Am I asking too many questions?
OK, I'll bite. A shack is someplace that's cheap, informal, kid friendly, and doesn't put goat cheese on anything. Often seasonal, sometimes not.
A hole is a place where the food may or may not make it worth risking your neck to venture to such a crummy area.
A dump is usually found just underneath a big yellow M :P
You just want good seafood, how about a little strip mall? Right on 44 in the same plaza with D'angelo and New England Pasta Company, is Deepwater Seafood.. Quite tasty if you ask me. Grab some frozen ravioli next door to take home with you, also very good.
I agree with everyone who has recommended 5 Guys. I've only been to the one in Farmington (next town over from Avon) but I imagine they are probably pretty consistent from one location to another.
Also one town away from Avon, but in the other direction, is Plan B in Simsbury (downtown in the old train station, the former One Way Fare). It's excellent.
I 2nd that....5 Guys is simply fantastic and fantastically simple! Easy to find, in the WalMart plaza, but don't let location discourage you. Peanuts in the shell to snack on, plenty of room to let the kids move around a little, fun atmosphere, clean, very friendly staff. On our first trip we got one burger and split it just to try it out. It was very, very good! I cannot drive thru Avon without my husband pleading to stop for their cajun fries! (Hit the Canton Auction Barn on 44, Sat night!)
Doogie's would fit the bill, in addition to hot dogs, burgers, they also have fried seafood and ice cream. I tried the fish and chips recently, and they were better than I anticipated. Try the steak and cheese!
Joe Pizza is a little place on Rt. 44 in Canton, just past the mall. They make the excellent burgers and pizza is good too.
I also second 5 Guys for burgers, their french fries are addictive.
If you've never been to a 5 guys Burgers and Fries and you're seeking a great burger---go there! There's one in Avon on Route 44. They pretty much only serve burgers, dogs and fries (no seafood, no veggie or turkey burgers) and I think they're awesome.
Doogies as referenced below is more of what it sounds like you're asking for but it's my opinion that Doogies is more of a hot dog joint (and their steak and cheese is pretty good too) but their burgers are meh when compared to 5 guys. Doogies does have seafood though...
enjoy your trip!