25. Snickers - "You're Not You When You're Hungry" (2010)
Betty White's remarkable relevance in her ninth decade of life is due to this commercial. This ad's viral popularity led to her hosting Saturday Night Live, which won her an Emmy. And the Snickers campaign itself is still going strong seven years later.
Photo Credits: Steve Granitz, WireImage; photo: Prashant Gupta / FX Networks; CBS Photo Archive, CBS via Getty Images; J. Vespa/Getty Images; ABC; NBC, NBC via Getty Images; Getty Images/NBC; Randy Shropshire/Getty Images; Sonja Flemming, CBS