Depends on what were discussing
For post unification, Dalmatia, part or all of of Slovenia, albania, some of the Greek islands, nice, corsica, savoy, malta....
Beat case scenario, say Italy does better in the wars of independence and annexed Trento, Dalmatia and Istria if and when ustria collapses, and clientizing croatia and Serbia. They ally with greater Germany (plus russia?) against France and Britain, take Tunisia, Algeria, tangiers, malta, egypt, cyprus. War with the Ottomans to take parts of anatolia and the levant (jerusalem, plus dominion over arabia and maybe iraq). Clientize spain and Greece. Maybe throw in a few asian colonies and a big chunk of africa.