Jennifer Aniston sported a hot one-shoulder black mini dress to take the stage at today's MTV Movie Awards in LA. She won the best dirtbag golden popcorn for her work in Horrible Bosses at the show. It's the first year for the category, and Jennifer's over-the-top performance helped her defeat competition including Bryce Dallas Howard in The Help. On stage, Jennifer accepted the MTV Movie Award and joked about her own good girl image, saying, "I mean, do you know how long I have tried to have somebody let me unleash my onscreen dirtbag? A really long time. And thank God this category just popped up. So I would like to say 'thank you' to the television show Friends for letting me unleash the inner sweetheart and here's to [Horrible Bosses director] Seth Gordon for allowing me to be a dirtbag."