Style Superstar: Lily Collins Slays Us At 'Mortal Instruments' Premiere

How superstylish is this week's Style Superstar? Let's put it this way: We still don't know which of her half-dozen amazing looks to highlight for today's feature, because she's been hitting it out of the park at every. Frikkin'. Appearance. Stop making our job difficult, Lily Collins! You go, Lily Collins!

But since we've gotta pick just one ensemble to demonstrate Lily's fashion savvy, we'll go with the one she donned for the L.A. premiere of "The Mortal Instruments: City of Bones"—a Cushnie et Ochs dress paired with white pumps and dark lipstick, a look which practically screamed "sexy and sophisticated," except that sexy and sophisticated people do not scream but rather purr like large cats. The artful cutouts on the dress's asymmetrical bodice gave this outfit plenty of edge, along with a sleek ponytail and dramatic makeup that left no doubt as to Lily's vamp cred and made her a shoo-in for Style Superstardom, and probably not for the last time.

Also showing a peek of midriff this week: Ashley Benson, who donned a two-piece ensemble and coral-pink shoes for an appearance at the Teen Choice Awards. And ooooh, we do love those shoes. But the skirt, with its busy mishmash of satin and lace and a lumpy bustle-like outcropping on the bum, is a serious misstep. And it looks like Ashley knew it: Her left arm is glued in the same position in every picture from the evening, probably because it was the only way to make the skirt's weirdness less obvious. We'll give her this: The girl knows how to pose!

What do you think of this week's best- and worst-dressed?