Jersey City Seafood and Meat?
For really high-quality seafood, drive north to Edgewater to Mitsuwa on River Road. It's a Japanese supermarket chain that is primarily on the West Coast. They also have Berkshire pork and a great Japanese food court.
Just moved to Westchester from Jersey City and I miss this place the most.
I like Supremo Market on Palisade (near Ravine) for fish. It's a neighborhood market, and they don't have very expensive fish, like sushi grade tuna, but if you want to make a good bouillabaise you should do alright. The inventory changes according to the day of the week, and if you wanted anything special you could ask for it.