Trapani has some excellent spots. Also consider a visit to the pre-medieval city of Erice, on a bluff overlooking the coast. Since it’s not right on the coast, the seafood is trucked up from Trapani, but there are some excellent small restaurants. Look for the “Couscous Oggi” signs that many places hang once a week. IIR different restaurants do different days. It’s been years but the chef at the restaurant at Hotel Elimo was particularly adept with seafood.
The ruins at Selenunte and Agrigento are worth a visit. Amazing to find Roman, Greek, and Etruscan ruins scattered about Sicily.