Which Daphne from the Great Plant Picks lists would be happiest as a planting against a house foundation receiving full sun with a western exposure, and which would have the best fragrance?
Of the Daphne species and cultivars listed on Great Plant Picks the only one which might not want full sun against a foundation or heat- and light-reflective surface would be Daphne odora ‘Aureomarginata.’ The others, if planted with sufficient distance from the house to grow into their natural shape, all like full sun for maximum flowering.
Intensity of fragrance is fairly subjective, and all these Daphnes are described as having notable fragrance. This article, from the Arnold Arboretum at Harvard, has some detailed descriptions.
One thing you could do is test the smell some of these plants in other gardens. We have examples of a few of them here at the Center for Urban Horticulture.
Another consideration is the ultimate size of the Daphne you select. Daphnes aren’t too pleased with being pruned, so choosing a species that won’t exceed the space you have available would be helpful.