Happy — Pharrell Williams (2013)

Written for the "Despicable Me 2" soundtrack, this infectious feel-good anthem spent 24 weeks in the US top ten and sold 6.7 million copies in its first year, making it the best-selling digital single of 2014. Its clap-along beat and universal message of joy outperformed #3 in US radio spins, logging over 3.8 million in total. Cheaper than the typical production of its peer songs, the minimalist arrangement proved that simplicity can dominate charts, earning a Grammy nod and becoming one of the top 10 best-selling singles of the decade.