A few Ranged bugs
Act 1 - Dank Cellar: As a DH (Not sure if other ranged can, but probably) you can attack the named from the doorway, and he will not even try to attack you, and you will get a free kill.
Act 1 - In the highlands, there is a bridge you cross over, where the middle of it has a portion that fell. If you kite enemies from the field, all the way to the bridge, at this choke point, they will get stuck, and will be unable to move past that point.
This is useful if you are having trouble surviving rare/champ packs. This will not work vs teleporter buffed champs or vs super small monsters, like burrowing leapers.
Act 2 - Zoltun Kulle bug - If you are ranged, there is a little indent on the circle in the middle, and if you run to it, while Zoltun is on the other side, he will simply freeze in place, and you can just blind shoot across the map and dps him down, and get a free kill. You only need to avoid tornados.
Act 4 - Rakanoth Perma Stun DH bug.
Get the following abilities/Runes as a DH:
Grenades - Poison rune
Cluster Arrow - Dazzling shot
Mark Of Death - Mortal Enemy
Reign of Veng - Flying Strike
This is useful for inferno Rakanoth.
Apply mark of death, Cast RoV ASAP, and cast whenever it is up. Then spam grendaes, and Cluster arrow, and make sure Mark Of Death stays applied.
What this does: Your poison damage will constantly regen your hatred, which will allow you to spam your stun arrow. Using this strat keeps him stunned in place for the entire fight, he will not teleport, or spawn a add a single time if done right. This is ideal for inferno difficulty as a solo DH.