Border Lord- has never rebloomed for me, but holds its color all day in very hot weather with many hours of sun (I divided the clump mid-July last year and it was still gorgeous this year-- the other half I moved to a little shadier spot and was rewarded with blooms that were saturated with even larger purple eye zones)
Evening Enchantment-great rebloom; holds color all day; the contrast of dark purple and very green throat make it difficult to get an accurate picture of its true color
Erin Lea- holds color well and gets a nice toothy edge when the weather gets hot (it has rebloomed, but not consistently)
Isolde-blooms early here and throws many poly blooms; holds its color very well on hot days; hard to set pods on
Red Volunteer
Ruby Spider
Shady Lady- sometimes reblooms in my garden
Siloam Peony Display-beautiful double blooms that last all day without drooping
These are just a few of my favorites. I purchased many new cultivars this year, so I'm sure my list will continue to change
I also love to share with friends and neighbors; I dug a few today that are going to a newly addicted daylily fan (pun intended). I plan to start a new garden at school this year so that my students can learn a little about genetics with real organisms.