Not sure what your requirements for "nice" are.
Last year at this time, we stayed for a week at the Shipshewana North Campground. It is just 3 miles north of town on State Road 5 (the main road in Town). There were some trees for shade, it was fairly quiet, the campers (mostly an older crowd) were very well behaved and the staff were friendly and helpful.
Link to Shipshewana North CampgroundRates were reasonable $30-40 per night, depending upon what hookups. And the best thing, a real ice cream store right next to the campground. We were very happy to stay there...most of our time was spent in town shopping, looking or going to nearby Elkhart to tour Jayco plant and RV hall of fame.