1. Inland Reef Aquaria = great staff, very clean, well stocked store, inspiring display tanks....you WANT to spent money there.
2. Paragon Aquatics = I haven't been to his retail store yet, but saw the quality of corals and rock in his garage. I'd give it a higher rating on coral selection than Inland Reef, but I have only been to Paragon once.
3. Aquadreams in western Mass. Their old store was in dire need of a face lift. They had a decent assortment of corals, fish and critters. I haven't been to their new store yet. I would check it out if I'm in the area but probably wouldn't go out of my way.
4. Reefsplendor south of Albany. I haven't heard a whole lot but it sounds like it would be worth the trip.
Heck you could make it a mini beach/reefing vacation, First Inland Reef Aquaria, then Coral Reef Aquarium in Seekonk, Ma. While you're near the Cape go to the beach and eat crab cakes and lobster. Then on to Paragon Aquatics, Aquadreams and Reefsplendor.