This is what I recommend often:
http://www.quiltshops.com
It's not one store, but a service comprising over 200 stores in a network. If you are looking for one particular thing, type it into the search box and then you will see all the stores that carry it. You can comparison shop for the best price. I've used this site since 2005 to purchase many things. I will say that all the stores in the network have easy ordering and fast shipping.