Not sure how much time you are willing to use to get there.
But a couple suggestions:
1. Drive along the Rhine river - it is beautiful.
2. Strasbourg or even better Colmar (smaller version of Strasbourg)
3. Freiburg has a nice old town center and university.
4. Lucerne is gorgeous, a nice walk along the water including historical bridges.
5. And you will pass by Lake Como and Lugano, both worth a stop.