What are your must have perennial flowers?

[Grandpadragon]

Anne Foulkard is a good one it has light green foliage and bright Cerise flowers - quite stunning although Buxton Blue takes some beating

Patrica is another really good one similar to ann foulkard and flowers its socks off all summer and well into Autumn. The blue varieties dont seem to flower for so long.
My other long flowering favourite is the Penstemons very wide range of colours