This is after a few hours of farming. We started at the sub-quest in Act 3 called The Second Heart, and we would progress through the Tower of the Damned, kill Cydaea, and then kill Azmodan. This was very profitable before 1.0.3 came out. I did one of these runs solo tonight, and I found some of the various elite packs to be pretty easy still, and with a 5 stack of NV I was getting 1-3 rares per pack. When I killed Cydaea I only got one rare. Same with Azmodan. This leads me to believe that the best farming method is to either start on the Kill Azmodan quest, and just visit every single waypoint looking for easy elites, or starting just before Siegebreaker and playing out the rest of the act.
This is actually a screenshot of my old build before the patch, but since they nerfed Nether Tentacles I have switched over to Ball Lightning. This is the only change that I have made. I don't see a lot of people using Shadow Power - Gloom, but it really shines on reflects damage packs, and Siegebreaker who now has reflects damage. I'll leave you with a couple of tips for the act 3 bosses that I have done post patch.
Siegebreaker: Siegebreaker now has reflects damage. If you incorporated Shadow Power - Gloom in to your build you should DPS Siegebreaker mostly when you have Gloom up. You can get away with a little outside of Gloom as long as you won't one-shot yourself. Just kite around until you get the discipline for Gloom. With good damage he should still die fairly quickly.
Cydaea: I had a lot of trouble with this boss at first because as part of the patch they improved the AI of her spiders. Since the spiders would one-shot me I had to play flawlessly, and get lucky with spiders not hitting me. I put her in the top left corner of my screen and burned her with Ball Lightning and Devouring Arrow to about 25% when she went up. The thing that kept me alive in the spider phase is that I was popping Gloom as I ran around, and I was hit by a few spiders, but Gloom mitigated a lot of the damage and allowed me to live. After she came back down I ran them to a corner, and shot a few Ball Lightning down the line of spiders. Got her to about 2% and did another phase two the same way as above, but used Smoke Screen at the end of it just to be safe. Takes some practice, or upgrading some of your most glass cannon items to live long enough.
Azmodan: Had to fight through two pool phases as I didn't have enough DPS to kill him before the second one. Same as it used to be before the patch. I dodge the meteors over Smoke Screening them because sometimes I have bad luck with pools, and I need the discipline for that. Try to lead him around the edge of the room, and leave the pools that way as well so you don't end up boxed in. Rinse and repeat for the next phase and then collect your one rare.
Hope these boss tips were helpful. Honestly, kill them once post patch just to show that you can, and then farm elites. The bosses aren't worth the new headaches that they provide, and the reduced number of rares that they now drop with 5 NV.