It was a busy week for celebs, with loads and loads of events that required beautiful outfits to go along with 'em. Two blonde Christinas were standouts -- Applegate in red carpet-ready Zac Posen and Aguilera in short and sexy Alaia-- in totally different ways, while actress Shailene Woodley, who is usually fresh and fun, stumbled mightily in a black Proenza Schouler two-piece which she paired with clunky, chunky heels.

The Best:

Christina Applegate:

The actress wore a lacy, charcoal Zac Posen gown that was as stunning in the back as it was in the front. The only complaint? That ponytail. While an updo was necessary to show off the back, a topknot or a chignon would have been a better and more elegant pairing for such a fancy dress.

Christina Applegate Zac Posen
Paul A. Hebert, Getty Images

Christina Aguilera:

Whoa! The singer was pretty in pink while promoting her return to 'The Voice' in a trumpet hem Alaia mini and nude Louboutin heels. Va-va-va-voom. What a bod and what boobies. We like Xtina when she chooses softer pink gloss and shimmery eye makeup, as opposed to her signature scarlet lipped, Old Hollywood glam look.

Christina Aguilera Alaia
Valerie Macon, Getty Images

Katy Perry:

At 'The Smurfs 2' premiere, the pop diva, who voices Smurfette in the film, turned up in a cobalt blue dress by Tadashi Shoji, which boasted a frilly, femme top and a leather skirt. The soft vs. tough juxtaposition of materials made this a winner.

Katy Perry Tadashi Shoji
Pacific Coast News

Jennifer Lopez:

The triple threat diva (actress/singer/designer) wore a summery, cream-colored Elie Saab frock, which popped against her eterna-bronzed skin. Three-quarter-length sleeves are in right now, so of course J to the Lo rocked 'em.

Jennifer Lopez Elie Saab
Slaven Vlasic, Getty Images

Angelina Jolie + Brad Pitt:

The power couple was decked out in all black, but what a dashing pair. Angie's Saint Lauren dress was simple but sophisticated. Girl could wear a burlap sack and look like a supermodel, but still...

Angeline Jolie Brad Pitt Saint Laurent
Ken Ishli, Getty Images

Rachel Bilson:

One of Hollywood's most fashionable actresses, Bilson makes the StarCrush Best Dressed list for the second week in a row, this time thanks to her sequined, '60s cut Philip Lim mini. It was as sexy as it was sweet.

Rachel Bilson Philip Lim
Jason Merritt, Getty Images

Anna Kendrick:

This twirly, ivory Temperley mini worn by Kendrick was mod and reminiscent of the '60s. The bell shape was utterly perfect for her body and the golden embellishing was darling.

Anna Kendrick Temperley London
Paul A. Hebert, Getty Images

The Worst:

Shailene Woodley:

'The Descendants' and 'The Secret Life of the American Teenager' star is adorbs, but her Proenza Schouler top and skirt did de nada for her. Neither did those chunky orthopedic shoes. No time for a pedi it seems, either. All wrong. All wrong.

Shailene Woodley Proenza Schouler
Jason Kempin, Getty Images

Amanda Seyfried:

The wide-eyed actress donned a ruffly, rich blue Givenchy with orange stitching --like jeans-- the styling of which was saloon waitress wannabe. The square bodice appeared ill-fitting, too. We just don't love it.

Amanda Seyfried Givenchy
Stephen Lovekin, Getty Images

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