The little black dress is just a Pandora’s Box, isn’t it?

We only need one, but there is no guarantee that one is actually the one. The next LBD we see looks even better. It could be the best ever. It could be the most Breakfast at Tiffany’s, the perfect Sex in the City. And we are looking for it all the time. Little-black-dress radar is never turned off. 

Photos from NYMag.com and Style.com

Designers understand this, because they must constantly reinvent the little troublemaker. This fall, Abaete (Saks, $270, top left) adds a sweetheart neckline and barely-there curves; Lanvin hits a bit of a harder edge with a sharp silhouette and a no-nonsense shoulder line (top right).

Michael Kors takes the hem up to here and the sleeves down to there, and ends up with a bit of a ’70s babydoll ($150. above left). Fendi adds buckles, buttons and a skinny little ruffle around the hem (above right).

Thakoon adds short little sleeves and a square neckline to a dress with a lot of shape (above left); Dries Van Noten adds colorful embellishment to his elbow-length bell sleeves, but otherwise comes up with a fairly shapeless dress (above center). Baby Phat owns the literal interpretation of the word “little,” in a dress small enough that it could roll up and fit into a nice Marc Jacobs bag (above right).

We give Bottega Veneta’s simple black off-the-shoulder sheath this year’s Hepburn nod (below left), for the dress most likely to get us down a Parisian street with confidence. Well, maybe except for Chanel, of course, and their hoodie-inspired leather dress (below right). We’re just not sure we have the, uh, je ne sais quoi needed to pull it off.

Photos from NYMag.com and Style.com.