Copper iris, witch hazel, and violet.
I love the natural violets we get. Our backyard has no lawn, just whatever natural ground cover grows. We move it about once a month. This fall we planted two blackberry bushes (native to our area) and I plan to add bareroot blueberries. When we can afford it, we will replace the Bradford Pears in the front yard with Chestnuts, which used to grow here. Baby steps.
I have to laugh about your violet recommendation. They like it too much here and come up by the thousands in the garden where I spend lots of time digging them out. I'd love to add witch hazel and a native iris someday though.