Three of my favourites are at their best now.
Smyrnium perfoliatum is biennial but it takes a little time to get a colony established.
If you can get hold of a pot of seedlings plant them as they are and leave them alone.
It is the greeny-yellow colour of a Euphorbia and stands at about 2’ high.
Chaerophyllum hirsutum ‘Roseum’ is far better behaved. It is perennial and has soft lilac mauve flowers. If you remove the spent flowers you are left with the delightful ferny foliage scented of apples.
Zizia aurea is also perennial, but shorter with neat yellow flowers and a tidy habit. It does not have the same presence as the other two but is an easy and reliable plant.