One of the beautiful reasons to visit Wisconsin in general is to experience farm life. Driving north of Delavan will bring you through some glorious farm land. Lake Delavan is a very clean lake and much more quiet than Lake Geneva.
About 20 minutes north of Delavan is the Kettle Morrain area. Bike paths, cross country skiing, horseback riding, and a fabulous place for nature walks. There are some beaches, the nicest I know is on Rice Lake in Whitewater. You can rent bikes at a great little shop on the corner of 12 and H. They also have deli sandwiches and a small snack store.
"Healthy Eating in Delavan"
On hwy 50 over by the Dairy Queen is a great Italian Deli called Riga-Toni's. You can dine in or carry out and get some of the best homemade Italian sausage ever! Next door to them is The Shrimp House with fantastic fish platters or shrimp to go. In the summer, George Williams University has Saturday concerts. Grab some shrimp and champagne and some lawn seats to experience a romantic and inexpensive evening. Most of the dining experiences in Delavan do not fall in the healthy category, but Riga-Toni's and Shrimp House are better than the rest.