Is there a trick to getting fresh fish?

I will on occasion make a trip to a fish market that is pretty far out of the way and it always seems to be really fresh, but when buying from HEB it pretty much turns out smelling / tasting "fishy". Am I missing some trick?

Edit: my question probably comes off as rude but that wasn't the intent. Love HEB but haven't had the best luck with buying fish there. I love pretty much every type of fish from Salmon, Grouper, Redfish, Tuna, Cod, etc but I feel like it isn't as fresh as it could be or are there fish types to typically avoid.