There are a wealth of studies documenting the health benefits of dark chocolate. Here are some places to get a taste of the power of chocolate:

Dr Warrens website with Testimonials, Research, History and more

Video - Dr Warren presenting the science behind good chocolate

Video - Dr Smith with focus on periodontal health and Xocai chocolate

A few of the hundreds of medical studies available on the web

• Effects of cocoa flavanols on risk factors for cardiovascular disease.
• Flavanol-rich cocoa induces nitric-oxide-dependent vasodilation in healthy humans
• Regular consumption of a flavanol-rich chocolate can improve oxidant stress in young soccer players
• Cocoa polyphenols and inflammatory mediators

There have been hundreds of news presentations and magazine articles regarding some of these studies... for example:

Cocoa 'Vitamin' Health Benefits Could Outshine Penicillin