Pets Inc in Tempe
No, I don't work here; if it wasn't 30 miles from home I'd try!
Great selection on freshwater and marine fish; if they don't have it, they can try to order it for you! I've received some nice farlowella that way. They also take in fish for store credit (likely plants too); they prefer to buy from local breeders.
Located on Southern and Mill, the northeast corner.