Best Wisconsin bike trails?

I and some friends want to take several rides on Wisconsin rail
trails, each maybe 20-30 miles long, and I'd like suggestions. We're
looking for the great trails and great parts of trails. The only ones
I know well are the ones between Trempealeau and Ellroy, so I don't
need suggestions about those (3) trails. But I'd like to hear what are
people's favorites. We think possibly the Red Cedar and Sugar River
trails are some of the best. Thanks for any other ideas.