The tiger lilies are particularly showy right now. I believe these are Lilium lancifolium, a species native to Asia that has become quite common in the eastern United States. It's a trouble free plant in my Mid-Atlantic backyard. Nothing eats it, no disease problems that I've noticed, rarely needs staking even when it gets quite tall. It tolerates a surprising amount of shade and still flowers, although the plants that are in the shadiest spots are the ones that sometimes need a stake. It spreads - lots of chubby dark brown bulblets in the leaf axils fall and take root, but it isn't difficult to pull up the extras.
A clump of tiger lilies has a bit of a wild, unkempt look. They won't all be exactly the same height, and even though they don't need staking, they'll lean a bit, in different directions. They make a bright summery statement in an informal garden.