The only frozen fish I eat comes out of the lakes and oceans caught and frozen by me. With the exception of the occasional crab leg or shrimp dinner when I eat out.
The only fresh fish I've ever ordered was Maine lobster, and there are a ton of suppliers to choose from if you go online. One I have used (for gifting), is Maine Lobster Direct. Recipients said the lobsters arrived alive as promised and other products were good. Living in Maine, I could pack and ship myself, but it's too much trouble.