This week's best and worst dressed celebs were a mixed bag. The First Lady Michelle Obama wore a bowed Carolina Herrera dress that might have been too cutesy on anyone else, while Jennifer Lopez went Southern Belle in a dress that wasn't hideous but it just wasn't ... her.

Here's who wore what this week.

The Best:

Michelle Obama

Her black Carolina Herrera frock boasted a bone colored bodice pattern and a sprinkling of bows. On her, the details were classic. On anyone else, it may have failed on a grand scale. Oh, and check out her dashing accessory.

Sean Gallup, Getty Images

Sandra Bullock

The ever-likable actress went with all black in a ASOS leather pencil skirt and a Michael Kors tops. Summer leather is everywhere, and Sandy went sexy.

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Kelly Osbourne

No need to call the fashion police here, as the TV host mixed several trends (black and white, stripes and leather) and the result was pinup cool. The length of her leather leggings was unique, as well. She was the epitome of rocker chic.

Dimitrios Kambouris, Getty Images

The Worst:

Jennifer Lopez

La Lopez went Scarlett O'Hara and June Cleaver with this "belle of the ball meets '50s housewife" ensemble at the unveiling of her star on the Hollywood Walk of Fame. The full peach skirt and white top by Dior were summery, yes, but sorta dowdy and out of character for this sexpot. Her windblown hair was also a miss.

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Sophia Bush

Why is the former 'One Tree Hill' actress dressing like Hugh Hefner in her Smythe suit? A smoking jacket with piping? Really? Menswear is a huge trend, but Bush didn't exactly nail it. The results here were too pajamaesque.

Larry Busacca, Getty Images