What is the best-selling candy in the world?

Snickers1.8
M&M's1.8
Trident1.7
Reese's1.4
Galaxy/Dove1.3
Milka1.3
Cadbury Dairy Milk1.3
Orbit1.3
Extra1.2
Kit Kat1
Mentos0.9
Other85
Sources: adage.com