I don't really like to enchant weapons, so I use a plain Ebony Bow mostly. I stock up on every type of arrow except iron (just buy out everyone's arrows so I have hundreds), and usually end up using Orcish or Dwarven the most, though I pull out Glass and Ebony arrows when the foes are tougher.
I do like to poison the bow a lot. Poison of Slow and Paralyze are good. Virulent Magicka potions are great against strong Mage enemies.