Just because she is returning to her country roots with her new album, doesn’t mean Jessica Simpson has lost her sexy image. The blonde bombshell entered the The Late Night with David Letterman show in a business-like black satin Diane von Furstenberg dress with a loose updo and conservative brown Jimmy Choo pumps. On the way out, the singer let her hair down and slipped into a seriously body-hugging Herve Leger dress. Jessica is proving to be an ultimate style chameleon the way she changes back and forth from country conservative to city sexy — in the same night! Tell us: What do you think is Jessica’s best look: conservative or sexy?