Husband and I both love decorative grasses and we've bought several kinds over the past few years. He occasionally gets excited about plants and buys things when we have no idea where they're going to go. The year before last he did this with miscanthus grasses (ETA: miscanthus sinensis adagio), and after they'd lived in pots on the patio for a month or more, we picked a spot (sort of a what-the-hell decision) and stuck 'em in the ground.
Whaddya know - they look really good!
I'm now somewhat in love with the concept of decorative grasses between or in front of evergreens.