Abu Dhabi is odd in the sense that there are only 2 kinds of nightlife. The first is the 5 star, VVIP type places in the newer and better hotels which, while good, can be a tad soulless if you go to the wrong places on the wrong nights. The second type is the real “spit and sawdust” dingy places which will either be awful and where you are likely to catch hepatitis or amazing fun. :) Not much middle ground that I can think of. The choice is yours @klcc88!
A good place to start your search for nightlife is Time Out Abu Dhabi, it gives a fairly good summary of what is happening and what is good.