EDIT: Seems as of 25 May, the quest rewards aren't as high anymore as shown in the video. Azmodan quest gives around 500 gold and Izaku quest 1k gold.
I thought sharing this way of farming gold and xp in Diablo 3. You can get 100k gold an hour and 1725000xp/hour. This is on nightmare mode which I think is the best mode to do it on if you are level 50+. If you do it on Hell mode it will only give you a bit more gold, but it takes way longer, unless you have super good gear.
This video was made yesterday evening where I finally dinged 60, a little bit after I cleared Hell mode.
I hope this will help you on your adventures. :)
Song: Ludovico Einaudi - Divenire