I love all kinds of fish and shellfish. I have never tried cockles but as I like most other types I'd probably like it too. My favorite is lobster, followed by mussels, oysters, and crab. I haven't had scallops in a long time, but they are lovely too.

I love them all apart from oysters. I would have to be on the point of dying from starvation before I had another one.
One of my favourite things to eat in France is Fruits de Mer - a socking great plateful of the stuff in its shells with dipping sauces and salad. Even better is when you order it for more than one - it then comes on a multi level cake plate.
Trouble is you need a big bucket for all the shells etc.
One of my best lunches ever was that with a cold beer on a harbour side in Brittany. It lasted a couple of hours.