C9Y Breaks off of US-52 closer to the Mississippi River, north of Balltown. Probably one of my favorites as well. I assume vwtom is referring to US-52, south of Dubuque, when mentioning "the river road down to Savanna."
If you haven't been to Balltown, do so, the roads leading there are all fairly nice. There's a nice overlook north of town. The stop at Breitbach's is usually fun, especially if you can avoid the crowd. Breitbach's has a buffet, but you can also order off a menu. Sunday Brunch is pretty good. The food isn't spectacular, but it always tends to put a smile on everyone's face.
Check out the roads between Elkader and Guttenburg. There are a number of roads between those two towns, that are fun rides.