I have a mix. I guess at this point mostly perennials. Ones I can think of in the yard include daffodils, wood hyacinths, iris, bleeding heart, daylilies, sweet peas, coreopsis, dahlias (can’t stay in the ground here over winter), heliopsis, feverfew, tradescantia, phlox, salvia, hostas, candytuft, opuntia and hellebores.
Ones that I can think of out there that can spread and get out of hand are lily of the valley, periwinkle, Chinese lanterns and mugwort. In April I started digging out all of the last two and am only keeping a few in pots.
Also consider what animals might like to dine on in your area. And look into native species to help out the birds and insects. Most of the plants I have are decades old now and many are not native.