I'm a big fan of Asian ceramic pots in the landscape and on roof gardens. These pots are made with an outdoor-ready clay and fired to a high enough temperature in the glazing process that they won't crack or break as readily as terra cotta.

Few things make as impressive a focal point as a beautifully glazed container, with or without plants in it. You will just want to make sure that the pots you buy are made to go outdoors in whatever area you live in.

The second thing to look for are drainage holes. If the pots don't have them already and you are planning to put plants in them, then you will need to either ask your supplier to drill them for you, or be prepared to do it yourself using a large drill bit of at least 1/2 to 1-inch diameter. Smaller holes will tend to clog up with dirt later on. It's a good idea to put at least 1-inch of pebbles or broken pottery pieces in the bottom of the container to keep too much soil from leaking out.