One thing I love about winter is how ornamental grasses stand out. Here's a switch grass that'll hold its shape until I take the shears to it in April. I have a number of Calamagrostis x acutiflora Karl Foerster and they seem to vary in attractiveness year to year depending on moisture and, possibly, soil. This swithgrass stays the same year after year though, and I love it.
This other clump of grass, on the right, even gets bigger year after year with no extra attention at all.