There are several great online stores for buying chocolate bars in the United States. Here are my five favorite places to shop (now, six, with the addition from Lowe's comment). These are the best online stores for buying chocolate that I've found. All of them have large selections of many excellent chocolate bars:
Caputo's has good prices and flat-rate USPS priority mail shipping of $7.99 regardless of order size. Click on See all brands link at the left to find chocolate bars by brand. Accepts MasterCard, Visa, American Express, Discover, and PayPal. Ships from Utah.
Chocolopolis has good prices and good shipping rates. Use the Shop By Brand drop-down at the top-left to find chocolate bars by brand. Accepts MasterCard, Visa, and American Express. Ships from Washington State.
Chocosphere has big selection and tends to have the lowest prices with slightly higher shipping rates, but includes warm weather packaging for free when they feel it is needed. Accepts MasterCard, Visa, American Express, and Discover. Ships from Oregon.
Cocova has a huge selection, but typically higher prices and slightly higher shipping rates. Accepts MasterCard, Visa, American Express, and Discover. Ships from Washington, D.C.
The Meadow has slightly higher prices and good shipping rates. Use Chocolate By Manufacturer to find chocolate bars by brand. Acccepts credit cards and PayPal. Ships from Oregon.
World Wide Chocolate has big selection and tends to higher prices and shipping rates, but also has sales every week, so there are opportunities for getting good deals. Accepts MasterCard, Visa, American Express, Discover, Optima, Diner's Club, and PayPal. Ships from New Hampshire.
If ordering during warm weather, be sure to add warm weather packaging to your order to make sure your chocolate arrives safely. Typical cost is around $7. Another consideration is the location from where your chocolate is being shipped because a longer time in transit increases the risk of damage.
In our individual bar reviews, we put a link to the least expensive price that we can find online at the time of the review (not including shipping charges). Because prices change, it's worth checking all five of the sites above if you're looking for a specific brand or bar.
Of course, a local chocolate store can be even better, as that may give you an opportunity to try a chocolate before buying! Plus, no damage in transit and no shipping charges to pay -- just your own transportation to the store. For example, here in Seattle, Chocolopolis has weekly happy hours during which they provide several chocolates to sample.
If you have a favorite online or local chocolate bar store, please add a comment to tell us about it (preferably with a link to their website). We'd love to learn about such stores in other countries, too!