I'd have to say honeysuckle. I don't have any but as I child we had them near my house. One of my Hoyas recently bloomed and the smell was so sweet my back porch was filled with bees. That's a close second. I've never had such a fragrant flower. It would hit you as soon as you stepped onto the porch.
I Love the smell of Tomato plants, Basil, Lemon Balm, Meyer Lemon tree & Lavender. And of course fresh mowed lawn <3
I agree with others: freshly mown grass is wonderful! I also love the scent of the ferns behind our house....I think they are hay scented ferns, so a common theme there. My other favorites are peonies!!! and basil. I just love basil. And tomatoes. The scent of basil and tomatoes = summer!
Freshly mown grass like everyone else, but also sweetpeas, tomato foliage, black currant foliage, daphne, jasmine......the list goes on
Tea olives and gardenias! So sweet that I always stop and take a couple of deep inspirations. They're not roses but they'll do.