If you've never been to Italy, start w/ the high points: Rome, Florence, Venice,
etc.
Once you've done that and are ready to branch out, the Dolomites are amazing. I lived in Milan for over three years, and spent many weekends in the Dolomites. Val de Funes is one of my favorite places on the planet.
One summer I spent over a week just in the Dolomites, loved it!