A friend of mine told me "You must try Arancini in Sicily." So I guess I'm gonna say the same thing: "You must try Arancini in Sicily." Though I would argue that Focaccia is better, I would leave that completely for you to be the judge of it. I will only say where I had the most wonderful experience in tasting them. It is the little bakery called "L'antica Arte Bianca."
The bakery is located on the small horn, on the North-East from Messina called Torre Faro. The area is known for the lakes, and I think one of them is called Lungo Lago. The address of the bakery is Via Nuova 51, ME 98164 Messina, Sicily, Italy.
There are two things that made me recommend this place. The first one is the incredible taste of the food it has there. They have Arancini, bread with olives, many different pastry that I do not remember the names of, and they have Focaccia. I learned there that there are several kinds of Focaccia. There is Focaccia with potatoes, there is a typical Messina Focaccia to try out. Though, the Focaccia that is served here is not as my friends told me that it should look like. Apparently, the original Focaccia has much more thicker dough. The Focaccia here more resembles a pizza. Never the less, it is very tasty. I say: "Try them all!"
The other thing about this bakery is about the people there. Though we had some moments of uncertainty due to my bad knowledge of very basic Italian, I got an incredible service. The baker offered me to taste all the things he had in the shop. By the time he was done giving me bits and pieces of food to try, I was full and could not eat the Arancini and Focacce I ordered. In those few minutes that I stayed there, I tasted all kinds of stuff, so I can easily say it is an incredible, good bakery. At that moment, since it was my first few hours of being in Sicily, I understood why people are so excited about Sicilian food.