Many ornamental grasses grow well in containers. A good one to start with is Purple fountain grass, which is easy to find in nurseries and big box stores once the weather warms up. It is an annual, which means it won't survive the winter where you live, but grows quickly once warm weather arrives. It has beautiful reddish purple leaves and nice flowers in late summer.

Some other good grasses for containers include various Miscanthus varieties, other fountain grasses (Pennisetum spp.), River oats (Chasmantium latifolium), Blue fescue (Festuca glauca), and various sedges (Carex spp).

I would avoid the large growing grasses such as Pampas. Make sure you have a large enough pot to accommodate growth, and use a good commercial soil mix that drains well.

I have grown purple fountain grass, Hamlyn fountain grass, Miscanthus "Little Kitten," blue fescue, and river oats in containers in our yard. All have done well. Purple fountain grass is the fastest growing and makes the biggest "statement." Most OGs like full sun or a lot of it, but river oats can take a lot of shade.