I like perennial nicotiana indoors and out. Summer phlox, both the white and magenta, can be used for height. I like to grow these perennials for their fragrance, too. Black-eyed Susans and purple coneflowers flower all summer. They are long-lasting cut flowers.
Asters are fall-flowering perennials worth considering for the cutting garden.
I've become a big bulb fan the past five years or so. Daffodils give us more for the money than most any I can think of. There are about seven species of iris I can't live without, but this spring freesias, anemones and ranunculus moved onto my alternating list of favorites. Amaryllis and agapanthus are perennial bulbs that stand strong in the garden and in the sturdy cut-glass deep bowl your grandmother left you. To extend the vase life of cut flowers, gather your flowers early in the morning when they are fresh.