Gaining some traction this year in the celebuverse and on the Web, Katy found herself up one spot from 2011. How did she do it? Well, with her divorce not yet finalized, the bubbly star got caught packing on the PDA with guitarist Robert Ackroyd from Florence + the Machine, at the Coachella Valley Music and Arts Festival. She then went on to release the concert documentary "Katy Perry: Part of Me," which revealed bits and pieces of why her marriage failed. She has since been linked with Hollywood's most notorious lothario, John Mayer.