I have many single peonies, love how how whole bushes look, though need to support a few of them because the flowers are very large.
Paeonia anomala
Little Red Gem and mollis
P. tenuifolia rosea
Nosegay
Early Scout
Claire de Lune
Chalice
Roselette, Claire de Lune and Merry Mayshine
Seedling
Seedling of Pink Vanguard
Athena
Scarlet O'Hara