5. Katy Perry, "I Kissed A Girl"
"I Kissed A Girl" created something of a summer dynasty. Since Katy Perry's first single produced by pop mastermind Dr. Luke topped the charts in 2008, they've soundtracked several more together with hits like 2010's "California Gurls," 2011's "Last Friday Nite (T.G.I.F.)" and, to a lesser extent, this year's "Birthday."