I won't step foot in Wal-Mart. I've never been inside a Wal-Mart and I will never go. I don't care if they are giving stuff away.
I have two (actually 3) fish stores that I go to. I like my Petco in Union Square Manhattan, because there is one employee, Wayne, who is just great. He really knows his stuff. You gotta talk specifically to Wayne though because their other employees told me to put two kissing gouramis and an angel fish in a 10G starter tank. Their tanks are *decent* if you catch them at the right time. They go through a lot of stock quick too, so you never see anything in their tanks with a hunched back, or just incredibly big and old.
I got to Marine Tropical in Park Slope Brooklyn...which is pretty good. They don't sell much supply or plants for fish, but the fish selection is good. I got my red eyed tetras that I current have there, and they were in great shape. Not a lot of ich or dead fish floating around in their tanks. I got a dwarf gourami there too, great fins, beautiful color, but the tetras ate him one weekend.
The last place I'll mention is in Clifton, NJ. Its a fish nirvana. Absolutely Fish its called. The tanks are immaculate, the stock is even better and the people there are just great.
I know this is a Wal-Mart fish thread, but I'd figure I'd throw in my 2 cents about fish stock.