The popularity of fragrance oils can vary depending on personal preferences and trends. However, some fragrance oils have consistently been top sellers due to their versatility and broad appeal. Here are some top-selling fragrance oils that have remained popular:

1. Vanilla: Vanilla is a timeless favorite, known for its sweet, comforting, and warm aroma.

2. Lavender: Lavender's soothing and calming properties make it a popular choice for relaxation and stress relief.

3. Sandalwood: Sandalwood offers a rich, woody, and exotic scent that's often used in perfumes and colognes.

4. Citrus: Citrus scents like lemon, orange, and grapefruit provide a refreshing and invigorating fragrance.

5. Eucalyptus: Eucalyptus is appreciated for its fresh and invigorating scent, often used for respiratory relief.

6. Coconut: The tropical and sweet aroma of coconut is ideal for creating a beachy, summer vibe.

7. Peppermint: Peppermint fragrance oil is refreshing and invigorating, perfect for a burst of energy.

8. Rose: The classic and romantic scent of roses is a favorite for special occasions and romantic settings.

9. Patchouli: Patchouli offers a distinctive, earthy, and musky fragrance that appeals to many.

10. Cinnamon Spice: Cinnamon spice is perfect for adding warmth and a cozy atmosphere, especially during the fall and winter.

11. Amber: Amber fragrance oil has a warm, resinous, and sweet aroma that exudes comfort and sophistication.

12. Oud: Oud, with its smoky, woody, and exotic notes, is a premium choice for a luxurious ambiance.

13. Musk: Musk adds a sensual and musky undertone to various fragrance combinations.

14. Fruit Fusion: A blend of various fruit fragrances can offer a fresh and lively atmosphere.

15. Tropical Escape: Combining tropical scents like coconut, pineapple, and mango creates a vacation-like ambiance.

Please note that the popularity of fragrance oils may vary by region and personal taste. When choosing a fragrance oil, consider your own preferences and the mood or ambiance you want to create in your space.