Cervia has a number of very good restaurants. For typical cuisine from Romagna, La Paia is an excellent restaurant with a traditional ambience on the outskirts of the city. For fish, a staple of the Cervia diet, Lo Scoglio, on the banks of the canal, is exquisite. Genny is an alternative.
In Milano Marittima, there are many expensive restaurants. Il Caminetto, undoubtedly one of the best seafood restaraunts in the area, is located here. Beware though: you might want to bring a very big amount of money if you wish to dine here. Peter Pan is a very good pizzeria in Milano Marittima, that has reasonable prices.