There are many types of Christmas trees that have unique scents, but some of the most popular options include pine, fir, and spruce trees. Pine trees are known for their fresh, invigorating scent, while fir trees have a more subtle, sweet smell. Spruce trees are known for their fresh, woodsy scent. Ultimately, the best-smelling Christmas tree is a matter of personal preference, so it's worth exploring different types of trees to find the one that appeals to your senses.