Whether you're heading off to a class reunion or walking the decks of a cruise ship, the little black dress is a no-fail option. Look for details that flatter your shape (strapless to show off great shoulders; waist details to optimize an hourglass shape) and pick a length anywhere from mini to right below the knee for the most versatile look.

Nordstrom.comA perfect little black dress is timeless; what it lacks it up-to-the-minute trendiness, it makes up for in classic elegance. This Suzy Chin Maggie Boutique black dress is such a LBD. Its flattering easy sheath shapes and cap sleeves in the front make way for a surprising (and sexy!) plunging V in the back.

Gap.comNeed something dressy, but wearable in the hot months? Gap's cotton LBD will fit the bill. It has one of those super-flattering necklines (it ties) that brings all of the focus up to the face, plus it has an empire waist to lengthen and slim your body (without all of the annoying fullness of all those tent dresses on the market). Best of all, it's priced right: $39.99.

Fashion BugInexpensive and flattering? We love it. This strapless little black dress features side ruching (slimming!) and a sassy hanky hem, all for less than $40.

eLuxury.comCocktail dressing doesn't mean you can't look like a lady: this Tracy Reese little black dress is the perfect example. It features a sexy but sweet scalloped neckline, belt and pockets.

Old NavyWhy let the jillionaires have all the fun? You'll look just as hot in a strapless black Old Navy dress for a mere $24.50 as any woman at the party!