This week's best ensembles were dresses --in leather and sequins, even in summer -- while the worst were largely menswear mishaps. Actress Naomi Watts owned in a black leather McQueen frock, while the usually quirky Maggie Gyllenhaal did the peplum trend in a unique yet all wrong way, adding pounds via an unflattering embellishment. The frock was by Dior, which made it even more confusing.

Here are our picks for the best and worst dressed stars this week.

The Best:

Naomi Watts

Oh look, it's black leather in summer ... yet again. The actress donned a femme Alexander McQueen frock and strappy heels, showing a lil' sideboobage.

Naomi Watts Alexander McQueen
Frederick M. Brown, Getty Images

Reese Witherspoon

With shoulder-skimming locks, the actress has bounced back from all that arrest nonsense in a strapless black micro-mini. Her Mary Alice Haney frock was so wearable, and that little flap of beaded fabric at the hem took this dress from just another LBD to smashing.

Reese Witherspoon Haney by Mary Alice Haney
Alberto E. Rodriguez, Getty Images

Sarah Jessica Parker

SJP shined in her multi-colored, striped n' sequined long-sleeved Marc Jacobs dress in London. She literally sparkled and wisely kept the accessories to a minimum since the dress had a lot going on. The smooth blowout was also smart since she didn't need a mane of wild curls competing with the dress.

Sarah Jessica Parker Marc Jacobs
Neil Mockford, Getty Images

The Worst:

Maggie Gyllenhaal

The onetime "It Girl" was confounding in a black and white strapless Dior with a knitted peplum waistline that added unflattering girth to her slim frame. It's a crochet project gone wrong ... all wrong. We still can't believe that Dior did this. 

Maggie Gyllenhaal Dior
Jamie McCarthy, Getty Images

Chloe Sevigny

Another lady known for being a fashion trendsetter tried too hard to rock the quirky menswear trend with high-waisted shorts -- or is that a skirt? -- and white Oxfords. No, no and no.

Chloe Sevigny
Rob Kim, Getty Images

Hayden Panettiere

The 'Nashville' star also erred with her menswear ensemble, which featured a sleeveless top with too-big bows and flood-length chinos. What the ...? That blouse is one present we don't want to unwrap.

Hayden Panettiere Menswear
Vittorio Zunino Celotto, Getty Images

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