Erysimum 'Winter Orchid' is my new favourite plant, which I now have in pots outside my back door. It flowers almost all year - honestly - and unlike traditional perennial wallflowers, its flowers are scented like the biennial forms.
Crocosmia Lucifer. Doesn't get more tropical looking than this without being tropical. Perennial, brilliant flame tubular flowers, sword like foliage,full sun.