Diablo 3 is not as entertaining as it was once you've beat Inferno difficulty and the only thing left to do is collect socketed rings. I have to admit that defeating Ghom was a huge pain in the butt.
I beat Ghom by spending about 200,000 gold in armor repairs and patiently learning to kite him very slowly around the small room. I had 40k health, 21k dps, 1200 loh (life on hit), 3% life steal, 6000 armor unbuffed (about ~10k buffed with keen eye), and 800 all resists. Here's the build I used against most act 3 and 4 bosses including Ghom. Here is the build that I used to kill Diablo three times (twice I helped friends and once I killed him myself -- and I feel like I could probably kill him solo whenever I wanted to get crappy loot.) Here's the build that I used for just killing elite packs in act 3 and 4. If I want to wander around act 1 or 2 to play with friends, I would go with a more agressive build. As a monk, I'd say a combination of life on hit and damage reduction (both from resists and armor) were my primary focus when looking for gear. Most of my skills served offensive and defensive rolls -- to boost my dps and still offer some aid in a fight. Using the terrain (doorways, stairs, etc.) was important. Also, using blind strategically to protect against the freezing balls from elites helped dramatically. (It's all about timing.) Good luck. Diablo was mostly a push over. Use Dashing Strike to get the heck out of the way of his firebreath, or out of the circles of fire, etc. He was nothing compared to Ghom who took hours for me to figure out.
In unrelated news, my book (Tritium Gambit) is available for Nook on Barnes and Noble's website: http://www.barnesandnoble.com/w/tritium-gambit-erik-hyrkas/1109407858?ean=2940014982054