Clotilde Soupert
Of all polyanthas I think this one is the best.  It does have one major drawback, which is that in early spring when the weather is cool and damp the many petalled blooms often ball, or fail to open.  Once it warms up most of the time they open just fine, and are so very beautiful that I can accept the early spring balling.  The plant is incredibly prolific - it blooms in huge flushes on and off all season if deadheaded.  The blooms are medium sized, very rounded and full, with creamy ivory outer petals with rosy pink centers.  The fragrance is heavy and sweet.  The plant is shrubby, sturdy, and well rounded.  It can grow and bloom in considerable shade.  The leaves are dark, glossy, and disease resistant.  It is almost perfect except for the balling in spring.  Bred by Soupert and Notting in Luxembourg in 1890, rated as hardy from zone 4.