Demon Hunter Elemental Arrow Build
Spec: The spec is the one that I use in a party of friends (typically I'm with a barbarian / monk / witch doctor.) The mouse clicks are obviously for dmg more geared towards aoe dmg.
Marked for Death is there for named mobs/bosses and buffing everyone's dmg, Vault/Smoke Screen are obviously for survivability and mobility. Shadow Power Blood Moon is really nice for bursts of extra dmg against bosses or large groups of mobs.
Passives: As far as passives go, Brooding works well with Smoke Screen for life gain when you start to get hit, Archery is always a nice passive and Vengeance works very nicely when you have 2+ melee fighters that are constantly grabbing the orbs (even if they don't realize it.)
Weapon Choice: At the moment, I'm using dual xbows because I just like the way it looks and handles. Not sure about the math on things like Elemental Shot or Hungering Arrow while dual xbowing, but I prefer it.
So far my setup has worked well with the group and we've cleared all acts on normal and are almost done with act1 on nightmare and will hopefully clear the rest of the acts soon.