PHOTOS: The Best, Worst & Wackiest Fashions Of The Week!

Leighton Meester is not known for having the most smashing sense of fashion, but the Gossip Girl experienced her career low on Tuesday, hitting the Harry Winston Court of Jewels Recreation Launch in a totally sheer Marchesa lace jumpsuit!  Paired with Nicholas Kirkwood heels and Harry Winston jewels, the plunging neckline number landed her the title of worst dressed star of the week!

Prince William and Kate Middleton announced their royal engagement to the world on Tuesday.  The princess-to-be showed off her ring---Princess Diana’s sapphire and diamond stunner—in total trendsetting a la mode.  Wearing an impeccably draped Issa number, which perfectly matched her blue bling, Kate spawned a fashion frenzy.  The dress sold out within twenty-four hours!

High fashion hit Hollywood movie premieres.

Christina Aguilera brought out the bombshell for the Los Angeles premiere of Burlesque, wearing an emerald green strapless Elie Saab gown, while Anne Hathaway was dressed to impress at a New York screening of Love & Other Drugs in a white Valentino number.

As for wacky fashion…

Courteney Cox’s absence can be noted, just by taking a look at David Arquette’s wardrobe of late!  The separated star has been hitting the Hollywood club scene, up to his old attire antics.  On Thursday night, we spotted the Scream star hanging out with a little friend, wearing a LOVE tank top from his Propr collection, with a single suspender over his shoulder.