What Were They Thinking?

Mischa Barton turned heads earlier this week upon arriving at Australia's Melbourne Cup horse race in yet another one of her eccentric ensembles. The former "O.C." star -- who nowadays lands an occasional supporting role in straight-to-DVD duds -- sought attention (received by the confused man in the background) by pairing an unflattering, layered frock with a mismatched headpiece fit for a royal ... not a D-lister.

A few days prior to Ms. Barton's style snafu, Nicole Kidman delivered an epic one of her own. Wearing a hat from the Cruella de Vil line -- and a bow-adorned lace dress from our worst nightmares -- the Oscar winner thoroughly embarrassed herself at a fashion faux pas-filled fete Down Under.

Lindsay Lohan + a lot of faux fur + what look to be lip injections + a lace tunic + 90 lbs. of hair extensions + biker shorts = nothing short of a fashion disaster. Yay, math!

Speaking of challenged follicles and rampant wig rumors, what do we make of Britney's mane these days? In addition to looking less-than-natural, the "Lucky" singer's locks are also looking a tad 1982.

Dear Demi Lovato, Enough with the top knots and white powder. You may think both are flattering, but -- truth be told -- both are frightening. Now, go wash your face and pull the pins outta that hairdon't.

How incredibly uncomfortable does Khloe Kardashian look in this long-sleeve mini? More importantly, how uncomfortable are you having to look at another Kardashian-infused photo?

Alan Cumming dressed as a bottle of Heinz ketchup for the BAFTA Britania Awards. Perhaps he can whip up another condiment-inspired ensemble next year. Perhaps a Grey Poupon getup?

Messy hair, a belted trench coat (with little underneath), and a sly smirk ... Is it just us, or does Penelope Cruz look like she's doing the walk of shame instead of attending a movie premiere? Just sayin'. (I don't think she looks that bad.)

As long as Russell Brand continues to wear legwarmers to yoga in relatively balmy Los Angeles, he'll continue to appear in What Were They Thinking?!.

What's worse, Beyonce's bang-enhanced helmet hair or her willingness to wear pajamas in public? Discuss!

So, which are the worst, which are okay, and which would you willingly wear?