Ron and Only Ron
Everyone in Professor Slughorn's sixth year, N.E.W.T. level Potions class knew that when Hermione Granger, when inhaling the smell of Amortentia, the most powerful love potion known to wizardkind, smelled freshly mown grass and new parchment and a third thing which she was far too embarrassed to reveal. However anyone who had been in her presence for the past couple of years and possessed half a brain could figure out that third thing was Ron Weasley. What they did not know was that, in actual fact, all three of these things smelled like Ron Weasley to her.
Hermione had always like the smell of new parchment, but she never got to smell it as much as when she was holding her paper up close to her face under the pretence of revising her essay, while really gazing across the room at Ron.
The smell of freshly mown grass had always been pleasing to Hermione, but never had it been more appealing than a recent summer at the Burrow. Mr. Weasley had long ago purchased a broken down Muggle lawnmower, and that summer, Ron had agreed to help him fix it up. However, the combination of ineptitude and overexcitement lead to a small explosion, leaving Ron smelling like freshly mown grass for days, despite multiple showers and Mrs. Weasley's frequent scouring charms.
And lastly was the smell of Ron, the same way he smelled everyday- a lovely mixture of the detergent the Hogwarts House Elves used on their robes, his deodorant, his mild cologne, his shampoo and his soap. This was the smell she smelled most often and loved the most. She smelled it every time he would reach across her at the breakfast table, every time he would look over her shoulder to read her essay, and every time he would lean over to whisper something in her ear.
When Hermione smells Amortentia, the most powerful love potion known to wizardkind, she does not smell new parchment, freshly mown grass, and Ron; she smells Ron and only Ron.