Up until a little over a year ago, I used to believe that good chocolate was measured simply by the proportion of cocoa in the chocolate. My favorite chocolate bars were the 85% and 70% bars from Green & Black's and Lindt that you could buy in some grocery stores.
I didn't consider that the type and quality of cocoa beans varies like that of coffee beans for coffee or grapes for wine, but of course it does.
Just as important to a chocolate bar are the other ingredients. In addition to cocoa solids, chocolate requires fat (best as cocoa butter) and a sweetener (typically sugar). Nearly all chocolates also use an emulsifier (to make the chocolate smoother, often in the form of lecithin) and flavoring (usually vanilla). Some chocolates also include other ingredients and flavorings (though the better chocolates seem not to).
I'm going to try to review and rate the chocolates I taste over the next 10 months. Admittedly, the rating part will be completely biased by my own preferences. Please note that the chocolates I taste here will be almost exclusively "dark" chocolates, with at least 50% cocoa solids, as those are the varieties I like best.
By the way, it turns out that Chocolopolis has its own blog.