If I had to pick one plant, shrub, or flower to have, and no other, it would be Hibiscus syriacus. It is most often referred to as Rose of Sharon, or hardy Hibiscus, or just Hibiscus.
My grandparents had Rose of Sharon bushes when I was a young child, and you could always count on seeing Hummingbirds on them.
Hummingbirds are attracted to the color red, but they will go to just about any color of flower. Many Rose of Sharon flowers have a red or pink center. They are available in a wide array of colors now, and more are being developed all the time. They can be purchased all ready to be planted in your yard or garden, or you can buy seeds.
They can be considered a large shrub, or small tree. With pruning, you can keep them at a more manageable size. When we first move to our home, there was one already growing, and we saw as many as 7 Hummingbirds at once on it. Since then, we have planted another one, and have had several that have come up from seeds.