Though there are over 150 Oils, I have listed the favourites below.

Oil
Description
Uses
Basil
Anise
Fatigue, Lack of Concentration, Migraine
Bergamot
Fresh citrusy
Depression, Stress, Tension
Chamomile
Fruity
Fatigue, Insomnia
Cinnamon
Spicy
Exhaustion
Clary Sage
Earthy
Exhaustion, Nervous Tension
Frankincense
Woody
Anxiety, Nervousness
Jasmine
Floral
Depression, Lethargy
Juniper
Coniferous
Psychic impurity
Lavender
Floral
Hypertension
Lemongrass
Lemony
Stress, Headaches
Marjoram
Herbaceous
Hypertension
Neroli
Floral
Insomnia
Patchouli
Earthy
Fatigue
Peppermint
Minty
Exhaustion, Nausea
Petitgrain
Floral
Stress, Aids Convalescence
Rose
Floral
Depression, Insomnia
Rosemary
Herbaceous
Exhaustion, Memory Loss
Sandalwood
Woody
Stress, Fatigue
Vetiver
Woody
Depression, Nervous Tension
Ylang Ylang
Slightly Fruity
Anxiety