It's not up there with spinach, but dark chocolate is usually your healthiest bet. The darker chocolate is, often the less fat and sugar it has.
Plus, dark chocolate usually is least processed -- that means it has the most antioxidant-like flavonoids, which may help lower blood pressure and cholesterol. The higher the percentage of cocoa, typically the more flavonoids the chocolate has.
But don't eat lots of chocolate in hopes of better health. A serving size is about the same as a package of dental floss.