The red forms of cordylines are stunning and resemble both phormiums and yuccas (which are also great architectural plants, especially the variegated ones).

Angelicas, amaranthus, and some sunflowers can also make great focal points. If you live in Arizona, I would think some of your barrel cacti or other forms of cactus would fill the bill.

azmountains_gardener,

Another candidate might be Red Leaf Castor Bean. The seeds are poisonous, however. It is also carried in some seed catalogs like Johnny's Selected Seeds.

ZM

Yes those suggestions (castor bean and Amaranthus) are right what i was thinking. There are different types of both shorter/taller. The Amaranthus Towers or Candleabra varieties are tall and stately, and easy to grow from seed!

How about some of the coloured corns like Zea mays Japonica (variegated foliage) or Fiesta? Also ornamental Millet or other tall grasses. (I am assuming by 'annual' you mean something you can sow and see mature in one year, rather than tender perennials like Phormiums.)

This is a long shot but...How about a Canna

Tropicana
Bengal Tiger
Stuttgart
Intrigue

Canna or banana would be good. Check out the Ensete Maurelli Banana. This grows quickly and is a real show stopper with dark sword like foliage.

You can buy starter plants on ebay at an affordable price.

What about Cardoon? It's large, unusual, has flowers and it's edible.

Here is a link that might be useful: Cardoon images

The last 3 suggestions aren't annuals. Not sure if that matters since the OP also posted on Perennials forum.

Flora the last three suggestions are annuals in our climate. If a plant cannot survive freezing for 3 months it is an annual in our climate.

It's a question of botanical nomenclature. I was interpreting 'annual' in the botanical sense, a plant which grows from seed, flowers and produces its own seed and dies all in one season. I would call perennials which do not survive the winter, tender perennials. They are still botanically-speaking perennials even if they die in some climates.

Cannas and bananas don't overwinter in my climate either, but I wouldn't call them annuals.

Flora you are correct but in the line of her question we were giving suggestions that she would not be able to expect to be a perennial in her garden and the best description for that would be annual for discussion sake not as informational of perennial, or annual.

In my climate I use a lot of plants that if I brought them inside for the winter they might survive but we use the term annuals for these plants. Maybe a odd wasteful gardening habit but it is what we do and how they are described.