Pet smart should have neons, and platys, guppys, loaches and cory's and snails. Wall mart is famous for carrying sick fish so I would be very careful with them, and petsmart is too, but it may be one that has a devoted fish employee. These fish are usually pretty common too.
Everyone says no barbs with the males because they nip fins, and a lot of people keep African dwarf frogs but I don't know anything about them. No goldfish, and no pleco species that get large.
If your thinking about a different type of fish, google it and see how big it gets, or post it on this thread so we can help you :)
Elrohir the plakat
Galah cockatoo & African Grey