I planted Fothergilla gardenii this year and it has excellent Fall color and interesting stem structure when the leaves are gone. I also have numerous "berry" plants, chokeberry, elderberry, and recently planted purple beautyberry. My pink pussy willow starts to develop its catkins in the Fall and those are of interest through the winter when there are no leaves on it. I enjoy watching them develop.
One of my faves for year-round interest is the evergreen hollies. Dark green color all year and the female plants have lovely red berries through much, if not all, of the winter. I like the conical shapes as well as the other various shapes.