I buy a lot of Jumbo Shrimp (Im hooked on the stuff), and will also ocasionally buy King Crab (Centolla) and Lobster - when prices are not completetly crazy... Im also a big fan of Octopus. With fish, Im mostly a Salmon guy, but will also get Lenguado (dont know the name in English), and Abadejo - which I prefer to Hake with doing Fish & Chips. I also buy a lot of Mussels (Mejillones)... great with Garlic and White Wine...

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