For the truest chocolate experience in the US, visit Burdicks in Harvard Square on Brattle street. I live in the square and it's a regular haunt for me. A truly decadent chocolate experience - the handmade stuff, the deserts et al. HOWEVER, for the wildest chocolate O.D. you've ever had, try their hot chocolate - the richest, most euphoric experience ever. You'll never be able to finish it all, so get it to go and put the other 1/2 in your fridge. The next day, you can eat with a spoon like chocolate moose! There, now you have one of my deepest darkest secrets!