I'll start with one of the easy ones:
Funspot in Laconia, NH is the region's pride and joy for well-maintained arcade games... as seen in the movie King of Kong... from the Wikipedia page:
Funspot Family Fun Center (or simply known as Funspot) is a video arcade and self-declared "classic gaming museum" founded in 1952 by Bob Lawton, and located in the village of Weirs Beach in Laconia, New Hampshire, USA. It includes over 500 games, an indoor golf center, a 20-lane ten-pin and candlepin bowling center, cash bingo, mini-golf, a restaurant, and a tavern. Funspot was officially named the "Largest Arcade in the World" by Guinness World Records at the 10th Annual International Classic Video Game and Pinball Tournament, held from May 29 through June 1, 2008.
Integrated within Funspot is the American Classic Arcade Museum, which is the first 501©(3) non-profit organization dedicated to restoring and displaying vintage coin-operated amusements. The museum celebrates the origins of the arcade industry with popular games from the past. Asteroids, Pac-Man, Centipede and Gorgar are just a few of the many games in the classic arcade museum. The museum also contains static displays of game history, and the walls feature many posters of vintage arcade games.
So, other great arcades, thrifts, and/or specialty stores in the region?