Our deciduous native azaleas in the Southeastern U.S. are wonderfully garden-worthy, and happily are appearing more in local gardens, and perhaps other parts of the temperate gardening world! They've all been flowering in the last few weeks - some of the nicest are Pinxter flower (a common name used for Rhododendron periclymenoides and R. canescens), both of which are lovely, and Florida azalea (Rhododendron austrinum). Florida azalea flowers vary in color from yellow to orange, sometimes quite vivid. This one was flowering behind my office building awhile ago.
They like filtered shade, and reasonably moist soil, similar to their natural habitat in the understory of mixed hardwood forests. They're definitely not in the category of adaptable natives, being fairly specific in their requirements!