Wild orange essential oil (Citrus sinensis) is one of my absolute faaaaaavorites! It's not as frequently used, and although regular orange oil can be readily found, wild orange is said to have more and stronger properties. Its aroma is obviously citrusy, but very sweet too. Use it in your car (a little plugin diffuser - makes a nicer driver), diffused in a room, or even a drop in a water bottle or smoothie.
It's most commonly used for digestive and immune support, as well as skin health. (You do need to be careful with topical use on the skin though, since it can make you photosensitive.) But I think of all its uses, the emotional impact it has on the mind and heart are probably the most popular.