I lived in Brunswick, ME for a couple of years, Wifey grew up in Bath. Taste of Maine is alright. It's the touristy place right off Rt 1 that will give you the "Maine Seafood Experience."
Starting in Portland, ME and working your way north: Benny's Famous Fried Clams (
http://bennysfamousfriedclams.weebly.com/) is the real-deal New England seafood shack. Just off Commercial Street in Portland, it's a tiny little hole in the wall off the beaten path and it's amazing. All of their seafood comes off the water that day and you can taste it.
Also in Portland: The Porthole. (
http://portholemaine.com/) Another hole in the wall, but literally right on Custom House Wharf in the Old Port. More suitable for a seafood lunch before spending the afternoon tooling around the Old Port and seeing what Portland has to offer.
Heading north to Yarmouth: Rt 1 south of Freeport has a couple of spots right next to each other. The Muddy Rudder (
http://muddy-rudder.com/) is a nice place for a sit down lunch or dinner, all the fixins, nice atmosphere, etc. Basically right next door is a little lobster shack called Day's Take Out (
http://www.dayscrabmeatandlobster.com/). They've got a couple of picnic tables out back by the water where you can eat your steamed lobster or clams, or you can go in to the store side and get them to go if you want to do a lobster bake at your leisure.
Continuing north into Brunswick, there's a little tiny drive-in seafood shack on Bath Road, just outside the old naval base, called Cameron's Lobster House (
http://www.yelp.com/biz/camerons-lobster-house-brunswick-4) that was a favorite of mine when I lived there. All the fantastic fresh-steamed or golden-fried clams, shrimp, scallops, and of course lobster rolls you could ask for.
And depending on how far off the beaten path you want to go, Wifey highly recommends the Five Islands Lobster Company (
http://fiveislandslobster.com/) in Georgetown, ME.