I've tried a number of low carb chocolates, the best to date are Pure de-Lite. They are amazing...if you like dark chocolates they are 0 Carbs. The only place i've been able to find them is through: http://www.cdnf.com/cat3_1.htm

They have a good selection, my favourite is the choc/coconut, 3.8g carbs for the whole bar...yummy