I don't buy a lot of fish (Jason doesn't like most fish), but when I do, it's usually at Han Ah Reum. The fish at the Englewood ShopRite is mostly pre-wrapped, they do have kosher fish (wrapped) at the fresh fish counter.
For the best fresh fish in the county, Maywood Seafood gourmet is worth a special trip. The very freshest fish ever, with some beautiful wild salmon (no coloring) really fresh clams, mussels, and lobsters and a variety of other market offerings. Don't be fooled by its hole-in-the-wall appearance.
Maywood Seafood Gourmet
103 West Pleasant Avenue
Maywood, NJ 07607