the one nobody got, which in my experience is the most common in andalusia, is rosada, or sea bream. delicious, usually served deep fried in a light batter with salad, and maybe patatas (chips in english, fries in american!).
another one to look out for on the south coast is prawn tortilla. thin crispy / crunchy and prawny!! lovely!!
for a special meal look out for dorada baked in a thick layer of salt. sounds awful but it's fantastic.
also, gambas: Gambas pil pil (sizzling in garlicky oil) or a la plancha (grilled in their shells and sprinkled with sea salt).
finally, on the beaches of malaga ( and elsewhere) are chiringuitos, little barbecue huts where sardines and prawns etc are barbecued to order. sardines are skewered - an espeto. lovely!