My family and I are lovers of Italian food and have tried unsuccessfully to find a cruiseline that offers what we like. We were Sitmar passengers and loved the food and true Italian service that they offered.
We have tried Princees twice and neither time was very impressed. Currently we have been sailing on the Celebrity ships (6 times) and feel the food is very good ,but of course, not Italian..
Our experiences on Costa and food or service have not been very good. We don't have the budget for SilverSea cruises, but is there any line out there offering "good Italian food"?
By the way, doesn't the family that once owned Sitmar also own SilverSea.?
The Seabourn Sun has a great Italian restaurant. It is pricey, but keep your eye open for special discounts. For authentic Italian and continental food some of the best I have had is on First European Cruises, based in Genoa - do a search in CruiseMates for the Mistral). Of course there are other drawbacks, like the entertainment and tours being presented in 4 different languages (the line is market to Europeans).
Having grown up in the NYC metro area in a half Italian family, most of the Italian food I've had on ships has been somewhat disappointing. It's certainly been edible and even enjoyable, but not really special.
So here's a suggestion ... take a Meditteranean cruise and have lunch or dinner ashore in Civitavecchia (Rome), Naples, Sardinia or any of the other Italian ports you may visit. There's nothing like going to the source!