Well I pretty much go there once a week and got a coupon from them for 30% off a 100 dollar purchase and thats when I bought the Clam and BTA. They also had a 30% off all live stock sale once (Maroon & Sixline). Its like 20% off on Sundays there too. The guys there are great and they take really great care of their tanks. I don't know how they do it but their sand is always pristine. Join their mailing list (in store) and they will keep you updated on what they get in.
House of Fins is good too, I get like 20% off with my ctars card there, but Greenwich is closer to me and easier to get to. House of Fins has a lot more dry goods, so I'll go there for that stuff. Most of the guys from Greenwich Aquria have worked at House of Fins at one point or another (or so they told me).
Exotic in Milford has the best prices I've seen so far but it is a lot more of a trip for me (since I work in Stamford).