You have 2 questions in your post, but only 1 vote!
Anyways, it depends on your build.
Any class that takes powerstrike, athletics, and puts wpf into a melee weapon will be good at melee. This will be archer OR xbow, depending on how you distribute your points. They are capable of being equally good at melee. With both styles you can take 6 athletics, 6 powerstrike, and put 70 wpf into 1 hand, for example.
Who does the most damage? It depends on which weapon you use. The short of it is:
Xbow is capable of the most damage per shot, I believe.
Archery is faster shooting so can do more damage over time.