lol well i personally have a vendetta against petco since they kicked me out of one of their stores for trying to take a picture of a lionfish. i have one of each within a couple miles of each other, i prefer the petsmart shop bc its cleaner, better organized, and it seems they have more knowledgable staff, however i also have a saltwater aquarium and they carry no saltwater fish... im torn... they are both cheaper than my LFS. generally anymore im disappointed with my LFS bc it seems they are more into dogs and cat grooming than fish keeping anymore, atleast the clerks they have seem to know more about giving dogs baths than fish... meh... petsmart is where i find myself buying filtration and fw fish stuffs mainly. between petsmart and walmart im covered on what i need. sadly it seems i find myself in situations without an answer when i try to use my local sources for a solution. it seems my best luck with technical and medical tank issues has been answered here. this is no understatement