as a first time aquarium keeper i've had great experiences at Exotic Pet Warehouse. The staff really tries to help and not just sell you something. they are honest about the fish and they are willing to explain which fish get along and which fish can not be in the same tank, which is great when some fish are not the simple $1.00 goldfish.
Soon as i start to brave the more expensive world of salt water, this is the only store i will be going to. AND more important, i have not seen the cruelly treated painted fish ever sold in the store.