I was a dedicated chocaholic, and still love it but eat it in small doses. I agree with all previous comments, and understand about polyols, but I have found that Thornton's "Diabetic" milk chocolate tastes really nice and never sends me scurrying to the loo. (Although I still only eat it in small doses) You can get it from all high street thorntons shops or online. My BG doesn't go up, but neither does it with ordinary milk chocolate in limited amounts (I have about 3 squares of cadburys now and again)
Beware, however, the "filled" chocalates, like My old faves, orange cream. The filling is pure sugar. Stick to just chocolate - the fat content reduces the effective GI of the sugars in the chocolate. Chocolate with nuts in is good, as the nuts themselves replace part of the pure chocolate weight and are good for you - low in carbs and low GI
My latest chocolate is Green and Blacks organic creamy milk chocolate. Normal chocolate, and really nice, but aboit 50grams of carbs (sugar!) per 100 compared to about 60 for Cadburys. Dark chocolate IS miles better, but no good if you don't like dark, and I don't!