Posting this as an 8wayrun exclusive. Presenting, the Critbomb Demon Hunter Spec.
Critbombers rely around a few key points to make this spec work.
1: Sharpshooter passive skill. This skill, obtained at level 50, builds up crit while you are out of battle. If you do not attack for long enough, you can guarantee yourself an automatic crit with any skill.
2: Fan of Knives with the Hail of Knives rune. What this does, is effectively give you: A very powerful AoE damage spell with very high range, and also: One of the most powerful fight starters I know of. The reason this works is because Sharpshooter is passively boosting your crit while not critting (read its text). Before a fight, this means that a 100% crit is attainable, and with a 100% crit, you can effectively force every single attack from Fan of Knives to critical hit on everything in range. You also drastically increase the range with the Hail of knives, allowing you to do terrible terrible damage vs. everything the group (or just you) is/are about to kill. This will usually wipe out "trash" mobs.
Now, you may say, that's all good and fun, but how do I set up maximum damage saturation by hitting the most targets?
Enter Number 3.
3:Vault with Rattling Roll upgrade. This serves all the function of normal Vault, but the rattling roll is a very specific tool.
Say your group is charging into battle, and you have a fully saved critbomb. Your tankiest character in the group obviously goes in first, so everything is close to him/her. You would Vault into the middle of the enemy group/s, and rattling roll would stun the mobs around your landing, giving you time to safely fire off Fan of Knives, spending your critbomb to drastically damage everything in 20 yards. Then, immediately vault back out to a safe distance and do standard Demon Hunter-ly things.
So, with how to use critbombs against groups covered, let's explore damaging stronger things, like Elites or Bosses.
4: Cluster Arrow with the Loaded for Bear option. Again, this is an AoE attack, but as AoE benefits from Critbombing so greatly, it is justified. You will do 290% weapon damage before crit with this, which means that even without critbombing, this is a very high-damage option. However, where it really shines in terms of critbombing is for taking on elites. With the central explosion dealing so much damage, and with the added bonus of critbombs, it becomes the go-to first strike against elite groups, because you are dealing much higher concentrated damage than say, Fan of Knives. This is your go-to hard hitter in this spec. Any time you open with this move, before this, you use:
5: Caltrops with the Bait the Trap option. Extra crit makes critbombs easier to attain, as well as giving you an easier retreat should a mob peel off onto you. This skill is really more optional, but I use this to shorten necessary charge times for critbomb, as having to wait longer just to have the DH build crit pisses off some groups, and you don't want to only rely on Sharpshooter to give you crit.
6:Additional notes: Other important mechanics of this build include: Archery passive skill with 2 hand crossbows (again, you should be building crit to make this spec more powerful, as critbombs are only guaranteed damage at the start of a fight), Numbing Traps (turns the Fan of Knives opening attack into damage mitigation for your tank, as well as buffing Caltrops), and Impale with the Chemical Burn upgrade (does a total of 375% weapon damage, and is your go to attack for taking down tougher single guys). Your primary mouse skill is entirely up to you, I use Grenades with Cluster Grenades (I am the AoE expert in my group.)
Here's the link to this build on the Diablo 3 site:
http://us.battle.net/d3/en/calculator/demon-hunter#UZYdhP!eVT!ZZcZbc
In a group setting, this spec works best with a group comprising of: You, a Tank specialist (as in, hard to kill dude that can at least somewhat keep damage off of the group), a character with high single target dps and decent crowd control abilities, and someone who can heal the group. So basically, Demon Hunter, Barbarian/Monk, Wizard, Monk.