Here are a few of my selections, planning to have them in my yard next year:
Lavender - looks great (blue color0, smells great, and it will make everyone want it in their gardens( http://www.bhg.com/gardening/plant-dictionary/herb/lavender/)
Yarrow ("coada soricelului" - achillea) - various colours, and can be easily grown, and it's also a perennial (http://www.bhg.com/gardening/plant-dictionary/perennial/yarrow/)
Agastache (desert sunrise) - orange bloom, with pink and lavender tints; but beware - it wants a lot of sun and dried land
Sundrops - yellow bloom, but it looks like it can be quite aggressive in the garden...
Russian Sage (http://www.bhg.com/gardening/plant-dictionary/perennial/russian-sage/) - tall plant, with lavender like colour and silvery foliage
Salvia - bush/meadow/mojave sage - yes, the aromatic version as well, seems to be a great plant for the dry gardens
Lamb's ears (urechi de iepure) - grows quickly, and can be quite invasive - but looks really great, in pictures at least
Pine-leaf penstemon - looks like a great one, with its scarlet red flowers and almost ever-green.
Blanket flower (gaillardia) - in blooms quite a lot, and looks really great with its bright shadows of yellow and red.
Purple coneflower (echinacea purpurea) - mauve-purple blooms the whole summer, and a perennial as well.
Amsonia (amsonia tabernaemontana) - looks like an unknown plant, although amazing through its blue colour, and the yellow shades in autumn.
Sedum - pure pink flowers in autumn... although there are many other types of sedum that have different colours as well.
So plenty of options - now I need to choose which ones to pick... tough one indeed!
P.S.: The photos on the page have been taken from web, so if you own any of those and want them removed - please let me know.