Daphnes are great for wafting fragrance, especially D. tangutica, which makes a 4' rounded shrub over time-
Daphne transatlantica has a rounded shape as well, but unfortunately can get unstable when it gets larger, the large one had half die off. This one I grew from a cutting and it was much cuter when smaller. It has cute little clusters of flowers and can bloom much longer than other Daphnes, even most of the summer, and perhaps a little into fall. It has a typical Daphne fragrance and can waft.
Mexican Orange Blossom, Choisya ternata, has slight but pleasant fragrance for me. It seems to bloom dependably for a while in spring.
I also have Choisya ternata 'Aztec Pearl', below. It has smaller leaves. It would probably benefit from being cut back some for a better shape, perhaps they both would. When the Mock Orange, Philadelphus, blooms later, it will totally eclipse these with it's intense fragrance, but much sparser display.
Another Collector's Nursery delight, fragrant Lonicera syringantha, Syringa being Lilac,;-) It is a very rangy wispy shrub with tiny clusters of tubular flowers, very fragrant up close.
And of course probably the most wafting fragrance now is Lilac,
My favorite native fragrant plant in my yard, just beginning to bloom, is Smilacina or Maianthemum racemosa, False Solomon's Seal. It grows wild in former woodsy places, but deer eat the flowers off sometimes. It is one of those intense heady scents that you have to close your eyes and really inhale, and I seem to feel it flowing through my senses and accomplishing some wonderful healing benefits. The other plant with this effect is not blooming yet, Valerian.
Strangely, true Solomon's Seal, Polygonatum odoratum, in spite of its name, has no scent for me. It seems to be coming up in some new places this year, I don't know how it got around. It has strange knobby rhizomes and has medicinal uses.
Take time to smell the flowers!