1. Place de la Republique in Strasbourg. Here you can find the National Theatre, National Academic Library, the Rhine Palace and the beautiful Monument aux Morts (a mother holds her two sons: one fought for Germany, the other for France, both are dying, but they're making peace.)
2. Leipp-Leininger in Barr, Alsace. This is the best place to taste Alsatian wines with a young wine grower, lot of explanations in French, German or English, and the wine is good.
3. Château du Haut-Barr in Saverne, Alsace. The castle is a ruin, but really impressive; it looks like a vessel of pink stone, with an amazing view of northern Alsace. You can even see Strasbourg from here when the weather is favourable.
4. The Maginot Line in the Vosges. See the remains of World War II bunkers that acted as part of the French defensive line. Be sure to bring a sweater (in summer too) because it's often cold here.
5. Légère, a little restaurant in Freiburg-im-Breisgau Niemensstraße 8, near Martinstor). At this restaurant you will find cheap but good traditional meals from southern Germany & Alsace, and also beers from the area. Be sure to try the Spätzele (3 cheese and traditional are the best). This place is popular with students, and gives you a good reason to visit Freiburg-im-Breisgau, a beautiful city.
Thank you, Xavier, for the suggestions. If anyone is traveling to Strasbourg or the Alsace-Lorraine area in 2012, get in touch with Xavier, for more local insight into the area.