Chocolate is an experience enjoyed by all five senses. Here are some of the qualities to look for in fine chocolate:

Look
The color of fine chocolate is natural and uniform. Appearance should be smooth and slightly shiny. A surface too shiny is likely due to preservatives or additives.
Smell
Fine chocolate has a fresh and deep aroma. Perfumed or sugary scents are signs of artificial flavors or preservatives. Its fillings should not overwhelm the chocolate coating.
Listen
How does your chocolate break? Except for a ganache or truffle without chocolate coating, the snap should be clean with a nice crisp sound.
Touch
Fine chocolate feels silky and starts to melt in your fingers. Chocolate that does not melt quickly may have been processed with hydrogenated vegetable oil that has a higher melting temperature.
Taste
Let the chocolate melt against the roof of your mouth. The quicker the chocolate melts in your mouth, the better the quality.
The texture should be smooth and silky. Gritty texture and waxy taste are signs of inferior ingredients and processing.
Fillings should be soft and smooth. The flavors should complement, not contradict each other. Hard and dry fillings are indications of age.