If you're a thrifty shopper, this Rebecca Minkoff Cross Body Bag will fit the bill. It's a foolproof choice, while not very costly. Another strong contender for your wardrobe is this Mackage Crossbody. While the price of this item is not very high, it will definitely attract a lot of attention. You might also want to consider this DKNY Crossbody Bag. The price is very reasonable, but the effect on your wardrobe will be pretty fantastic.
If you're not the one to skimp on clothes, then what you're looking for is this Bloomingdale's Crossbody. It's more expensive but worth your money.