I have been to Venice as a child with my family, and also with my wife years later. It's a beautiful and magical "floating city on the water"

For that matter other "must sees" are Tuscany region, including of course Florence (Firenze), magical Lago di Como, the City of Rome of course, Genoa, etc. Its truly never ending in beauty and mystique.

For me, because of my heritage, all of the south also means so much to me. Napoli, Calabria, Sicily (especially Northwestern Sicily). Beauty in whichever direction you turn your head.