Which is better for you? light, dark or medium roast coffee? are there any pros or cons of each?

Not much difference: It is mostly a matter of taste. Some studies indicate that dark roast coffees have more antioxidants so may have more health benefits. If you are interested in the health benefits of coffee you need to drink it black and without sugar.

It's not the coffee.: It's what you put into your coffee that generally makes it unhealthy - sugars, artificial sweeteners, heavy cream, whole milk and flavoring syrups. A cup of black coffee, regardless of the type, only has around ten calories.

What do you like?: No difference, the darker roasts have more caffeine. Be mindful of what you put in it. No clear pros/cons of either.