I would personally suggest 2H
bow for those who do not want to depend on crits completely and like a hasty and mobile play (yes gameplay is possible without shapshooter passive! I sort of grow tired of ppl telling me they reach 50K dps for one shot and being 15k after :-D )
crossbow for those who do know how to play carefully and can deliver those fatal oneshot kills
(in inferno this is challenging indeed!)
for the following reasons:
1. it's cheaper - to get a decent 2H is at least half the price to get two decent one hands, quiver comes cheaply ( I have +80 dex/ 192 vit quiver for 200K)
2. more weapon dmg - yes that sort of relevant thing that all your skills stack of
3. lower attack speed - many people stack atk speed to reach maximum dps, making slower weapons more desirable for maintaining resource managment (this of course does not account for the discipline restoring passive, who exactly is using that? Not me, sorry.)
To conclude, I play with a Bow, I used to lvl up and play with a crossbow, it is imho the way to go since DHs are the only ones who get to have offhand with a two hand making 2Hs much more viable than to all other classes.
I am using this solo build http://us.battle.net/d3/en/calculator/demon-hunter#fRdSXV!aeY!bcbcZb
I got off some guide, it's creative and effective.