This is what it looks like:
#1 - Caltrops + Torturous Ground for instant stun, slow, and lock on ALL mobs. (Note - Can be used multiple times because cost is only 6 discipline so it's great for kiting)
#2 - Companion + Bat Companion for increased hatred generation. (Note - This will become very helpful when you are using rapid fire all the time to desolate mobs)
#3 - Fan of Knives + Hail of Knives for when you get trapped in a big group of mobs to instantly destroy everything around you. Mind you it does 320% wweapon damage and slows them + the radius is 20 yards so you absolutely get everything near you. + It does not cost that much hatred and with the hatred generation you can use this every 10 seconds and 10 seconds goes by very quick so you can use it all the time.
#4 - Grenades + Tinkerer for 6 hatred generation a second mainly. I use this only for when I see a bunch of mobs or need my hatred up in a matter of seconds, other wise I'm using rapid fire and bola shot all the time.
Left Click - Rapid Fire + Web Shot for insane damage and slow everything. Right now my DPS is 1500 and I basically kill all mobs in less than a second with Steady Aim Archery and Cull the Weak activated all the time. + When you have Caltrops and they're slowed and stunned because of that you absolutely destroy. Elites and rares used to be a problem for me when I used chakrams (which I really love but right now it's just not as accurate or viable to me for groups of mobs or even single mobs for that matter compared to the accuracy and radius explosion on Bola Shot). Bosses die within under 30 seconds to a minute in Nightmare. I know the hatred cost is 20 which can be expensive if not used properly but with all the hatred generation this skill seems to be the most OP out there for the DH. I have tested all other spells and skills and nothing compares to the current set up I have right now, so I'm not really sure why I see people saying they're using Impale and Elemental Arrow and other not so good spells... maybe that's what works for them but this build is godly for me right now.
Right Click - Bola Shot + Volatile Explosives for great destruction of multiple mobs at a time and increased hate generation. I often spam this and Grenades at the same time to get hate up almost immediately and do great AOE damage. The crits on Bola Shot are also very impressive.
Passive skills are Steady Aim, Archery, and Cull the Weak. Of course for all the extra damage... It is also to be noted that I have 7k life at level 42 which seems to be enough for me right now. I've stacked all Dex, Vita, and Life Steal gear so even when I do get hit I just throw down Fan of Knives and I'm immediately back up to full health. I used to use potions a lot until I figured out how to work this class better and now I never use them and I'm in Act 3 Nightmare...
My rotation when I immediately approach enemies is Caltrops + Rapid Fire to destroy everything real quick then I destroy groups with Bola Shot + Spammed Grenades to regen hatred and then quickly back up to Rapid Fire to keep annihilating. Bat companion is out all the time for hate generation like I said if I ever get stuck I just blast Fan of Knives and everything is dead.
I hope this honest review of my DH and her current skills will help people out. If anyone has any questions please let know and I'll be happy to answer them.
Here is the link to the build. http://us.battle.net/d3/en/calculator/demon-hunter#cWYThU!Yec!ZaZZba