It's a tie between

"I Kissed a Girl" By Katy Perry

and

"Blah Blah Blah" By Ke$ha

The first is objectifying women, cheapening homosexuality to entertainment, and basically encouraging girls to be lesbians for attention and that it's okay to lead someone else on regardless of weather or not you are in a relationship.

The second is objectifying men, while the 'singer' says how "Empowering" it is for women to talk about men the same way men talk about women in their rap songs, because EVERYONE knows that hypocrisy is empowering.
Plus TALKING in rhyme while auto-tuned =/= singing.