Sicily has a long history of foreign domination, from the Greeks to the Romans, Arabs, Normans, Aragonese. The result is a mixed culture where every single domination left something to see, to taste, to hear.
Sicily is a huge island where every little city seem to have its own culture. You will find great variety of local specialities in all cities over the island.
What else? They are proud people and most of them are a little bit conservative, but open-minded to visitors.