WEEK OF MARCH 31, 2009: Young Hollywood There is a new crop of young starlets out there who are doing their best to push fashion forward. This week we rounded up some of the best dressed of this new class of fashion mavens. Sprouting out of the Disney and Family Channels they are just at the cusp of breaking into the big leagues. Many on our best dressed list, including Miss Blake Lively, also made it on to the infamous Vanity Fair's Hollywood: The New Wave, a list that predicts the next generation of Hollywood A-listers. One such young celeb whose star is about to light up a multitude of big screens is Kate Mara. She outshone many a leading lady in her pink ruffle Dior number at the opening for the Annenberg Space for Photography in Los Angeles.   BEST ONE-SIDED Gossip Girl star Blake Lively showed up to a taping of David Letterman in a hot, hot, HOT fuschia one-shoulder Diane von Furstenberg dress.   BEST BOOTIE Emma Roberts rocked her Jimmy Choo booties on the orange carpet of the Nickelodeon Kid's Choice Awards paired with a red lace Dolce and Gabbana mini.   BEST INCOGNITO Camilla Belle kept a low profile while out on a strole with her beau Joe Jonas but still managed to look super stylish with a head scarf and oversized sunglasses.   BEST BIKER Vanessa Hudgens created a tough biker chick look with her leather jacket and a pair of black studded knee-high boots while out with Zac Effron.