Okay if you go with a Hydra or Crusader Bow, which are the bows with the highest damage. They both have the same speed, being fast. Gothic Bows, Long War Bows, Long Siege Bows, and Long Battle Bows are the other bows you can get with 6 sockets. However they all do less damage. Hydra does 10-68 and Crusader does 15-63 so those are your choices.

Or you can go with a crossbow. Either a Colossus Crossbow, Balista, Heavy Crossbow, which can all have 6 sockets. The Colossus Crossbow does the most damage at 32-91 and has a very slow attack speed. But will give you the most damage of any botd bow.

Who Delivers ten times out of ten?