personal judgement.
In terms of the everyday variety, the chain stores will consistantly stock the same kinds of fish in great quantity, so if u want the more common fishies, then thats ur choice. But, because they get so much stock, alot of them die off, and in general, IMO!!! the staff arent nearly as "informative" as the LFS ones.
Now, this is stricly me speaking. I have had my beefs with LFS. There is one close to where I work that just doesnt have the same knowledgable friendly staff as the one near to my house. And, I have had issues with them selling the fish to me and not caring about how they handle them nor the condition of fish prior to selling them. My g/f has had 5 fish die within a couple days of that place. Not because of water conditions and such, but the fish were fin-torn and beat up. Thankfully the ones that DID make it are now flourishing and are fully 'finned' again.
My opinion is that LFS are something that needs to be researched, walk in, ask questions, browse the tanks, how do the fish look? Happy? Stressed?
Chain stores just sell quantity over quality. They are good for the hardy fish