This is based on the Billboard Hot 100. Billboard also has an official top 100 songs of 2014. However, it varies slightly from this list because it counts November 2013 - October 2014.
1. All About That Base, Meghan Trainor (4th biggest song of the decade)
2. Dark Horse, Katy Perry Featuring Juicy J (tied for 5th biggest of the decade)
3. Happy, Pharrell Williams (8th biggest of the decade)
4. All Of Me, John Legend (9th biggest of the decade)
5. Fancy, Iggy Azalea Featuring Charli XCX (tied for 16th biggest of the decade)
6. Shake It Off, Taylor Swift
7. Problem, Ariana Grande Featuring Iggy Azalea
8. Talk Dirty, Jason Derulo Featuring 2 Chainz
9. Rude, MAGIC!
10. Stay With Me, Sam Smith
11. Bang Bang, Jessie J, Ariana Grande & Nicki Minaj
12. Counting Stars, One Republic
13. Timber, Pitbull Featuring Ke$ha
14. Am I Wrong, Nico & Vins
15. Black Widow, Iggy Azalea Featuring Rita Orta
16 (tied). Say Something, A Great Big World & Christina Aguilera
16 (tied). Animals, Maroon 5
18. Turn Down For What, DJ Snake & Lil Jon
19. Pompeii, Bastille
20. Habits, Tove Lo
What is your favorite and least favorite of the list? What songs do you wish were on there but didn't make the cut?