Mild fish, such as lemon sole, suit a classic Italian white like Pinot Grigio or Soave, as these wines enhance, rather than overwhelm flavours.
Oily and meaty fish can stand up to quite bold flavours, both in terms of the dish ingredients and the wine you drink alongside them. A rosé retains a little of the texture you would expect to find in a red wine, so works really well with salmon. A rich cod and chorizo stew can blend with a light red - a young Rioja, for example, would be subtle yet strong enough to match it.
For Atlantic mackerel and sardines, fresh from the coast of Spain and Portugal, it makes sense that a compatriot like an Albariño would be a good choice.
With seafood, try a classic Muscadet or a good fizz, made by the traditional method. Or if you want to keep it more local, serve English sparkling wine with some home-grown scallops.
And for a simple fish and chip supper a bottle of Champagne is the best!