I have a lot of those so-so fragrant plants as well but here's my experience with:

Clerodendrum trichotomum: I can smell this from across a street. A friend has this as a small tree and apart from the fragrance, this has a lot going for it. Blooms late summer when there aren't too many blooming trees.

Clethra alnifolia: Good fragrance

Daphne: I don't have the same cultivars but all of the ones I have are very fragrant (caucasica, cneorum, cneorum Porteous, mezereum, x eschmanii) and plan on getting more.

Hamameles: have been trying to find a fragrant one for several years but haven't whiffed a good one yet. I was told that h.virginiana has the best fragrance but no personal experience and can't find one here.

Chimonanthes: My own plants are still young, but c.praecox is very fragrant.

Lonicera fragrantissima: Good fragrance. Don't know about the others.

Osmanthus burkwoodii: My plant is only 3' and it does flower but I don't find it very fragrant at all. I did have an Osmanthus fragrans which was only a foot tall but it was definitely very fragrant.

Phillyrea angustifolia: never heard of this one but will have to look into it.

Sarcococca hookeriana humilis: cannot decide about this one. It does smell good but depends on the weather and it is a shortie so perhaps the taller varieties would be better.

Osmanthus heterophyllus, Hamamelis vernalis, and Clethra alniflora are my choice plants. I would caution you about the really
unwelcome Clerodendrum trichotomum leaves.

Ankrara's Hobby Corner

"really unwelcome Clerodendrum trichotomum leaves"
What does that mean?

That's a nice list! I'll give you my nose's opinion, but there's no substitute for personal experience. Also, I'm sure you're thinking about what spaces and exposures you have -- clethra, daphne and lonicera need decent sun to perform best, while sarcoccoca needs dry shade.

Chlerodendrum trichotomum: pretty tree, nice but not great fragrance, it's the leaves that stink if bruised, hence, "unwelcome", also, they can be untidy when they drop in autumn.

Clethra alniflora: Sweet scent, not my favorite, but lots of folks love 'em, and they're tough.

Daphne bholua, D. burkwoodii, D. odora: can only comment on the last two -- very sweet, intense fragrance, but make sure you've got well-drained soil and protect them from strong winds, they have small, tender root systems.

Hamamelis: I love my vernalis 'Sandra' -- it blooms in February, the scent is light but clean and floral. Most fragrant are h. mollis and it's hybrids. H. virginiana blooms in late fall, scent can be strong or weak depending on the cultivar. Check out Fairweather gardens (no website, but they'll send you a fall catalog), they have a great selection!

Chimonanthus zhetangenis? Don't know this one.

Lonicera fragrantissima, L. purpusii, L. standishii: first two are species, second is the hybrid between the two. Possibly my favorite hardy fragrant shrub -- the lemony scent is fantastic in late winter/early spring, and it's a very tough shrub. Out of flower, can look a bit ungraceful, but I don't care!
L. periclymenum: vine, long flowering season, very pretty blooms, scent not as strong as l. japonicum but really nice, almost wine-like. Japonicum is very invasive, so it's a no-no in my book.

Osmanthus burkwoodii, O. heterophyllus: These are both nice, but o. fragrans has a longer bloom season, is hardy in your zone, and is perhaps my favorite tender fragrant shrub. One of the all-time best fresh apricot-like scents!

Phillyrea angustifolia -- supposed to smell like grape soda.

Sarcocca confusa, S. hookeriana humilis, S. ruscifolia: scent can be faint in my experience, but it's a winter bloomer and they make a great ground cover shrub.

Hope this helps!

Jim

Thanks for the replies, wow, you guys must have a lot of fragrant plants. Are there any that I don't have listed that are a must have? I've already got M. figo, M. skinneria, M. maudie, mahonias, citrus, night blooming jasmines, sambac jasmines, and star jasmines. I also have around 30 Osmanthus fragrans, I love them and that's why I'm looking into other varieties of osmanthus.

what, no gardenia? they have glossy evergreen foliage, as well as being intensely fragrant.
calycanthus floridus 'athens' has a nice fragrance and is native.
not a shrub but hedychium coronarium is one of the hardiest gingers and should grow in your zone. it is a good perennial for late bloom and fragrance.

OOOPS
I also have gardenias and calycanthus floridus (not 'athens', though) and gingers.

Clerodendrum trichotomum flowers do not have an entirely sweet scent. Sweet with an acrid undertone might be a good description. I like the scent, but many people hate it. Also, the blue fruit are pretty, but often produce a lot of volunteers. Butterflies love the flowers!

Hamamelis mollis is supposed to have the most scent. Mine ( 'Goldcrest') had a nice scent last winter. I was never able to get much off the intermedia cultivars. Daphne odora 'Alba' is divine.

hamamelis mollis 'Pallida' is definitely the most fragrant and beautiful -- to me at least. It may be a little harder to find (propagate) and get going. You could also consider investigating the beautiful corylopsis family if you have the space, and loropetalum, which is in the family, I believe, and which can be smelled from a block away.

Monarda,
I have never in my life smelled a loropetalum, and they are blooming everywhere (even in my yard) right now. Which varieties are fragrant? Or is it just that my nose can't smell this smell? We are talking about the same shrub, aren't we? The one with multi colored leaves that bloom bright pink wispy things in early spring?
I do have the space, tell me more about the corylopsis family.

I was at the Brooklyn Botanic Gardens yesterday, and the witch-hazels were out! 'Arnold's Promise' generally gets good marks for fragrance, but I found some of the orange cultivars had a spicier, almost orange-blossom fragrance to them.

Chionanthus (wintersweet) was fantastic: it's not very good-looking at other seasons, but it's hard to find a better winter-fragrant shrub, I could drink in the scent all day.

Winter honeysuckle wasn't open yet, except for a bloom or two, but it's my absolute fave winter bloomer, so I'll take what I can get. Sarcococca hookerana was just opening up, but I find the smell very faint.

I saw one corylopsis in the Japanese garden, looking quietly elegant with its short chains of bloom, but couldn't get close enough to smell.

I've likewise heard loropetalum can be fragrant, but never got much scent from any I've smelled; I'd suspect the white cultivars would be more scented than those bred for leaf and flower color.

Spring's on the way!

Jim

There were some bushes of Loropetalum across the street from the University of North Carolina at Chapel hill when I lived there in the 1970s. I could smell them from a block away when parking my car. They were white flowered and flowered briefly in the spring. The scent was fantastic. They are not hardy here in the North. I have seen red ones in catalogs but don't know if these are fragrant, too.

I've never seen a white lorepetalum. Maybe that explains it. I'll have to look for one. They are all hot pink here.

I have a seedling white loropetalum about five feet tall. I've never noticed any fragrance from the blooms, which are prolific. The last hard freeze killed the blossoms that were open, but there are buds yet to open. I'll sniff closer.

The hot pink are marketed because they're flashy. The white are thought by Dirr not to be of commercial value. Pity.

I noticed the clerodendrum posts. Clerodendrum bungeii, the infamous thug, has beautiful blooms (sometimes mistaken for some kind of hydrangea) that smell of Cashmere Bouquet soap. The large, pretty, dark leaves when bruised smell of skunk, really acrid. The suckers will fill a garden, so it's labor intensive, keeping it in bounds. It's not a desirable garden plant, but butterflies love it and so do I. I just plant other thugs with it and let them fight for space.

Nell

what about vitex agnus castus? my favorite for perfume.
best,
mindy

Ribes Odoratum; Buffalo Currant, AKA Clove Currant. 4 to 5 ft high and round in zone 7.
Yellow flowers early in the spring; strong, practically edible scent that wafts across the yard. I've had people arrive at my home, and, once they caught a whiff of the sweet, slightly spicy scent (think of old fashioned pinks, or climbing petunias), wandered around the yard until they found it before they came to the front door. Heavenly.