I've mildly kept aware of Gods & Kings ever since it came out, and of the general opinion that it does represent a good improvement to Civilization V. It seemed silly to pay full price when the base game had been only $7.50, so I waited for a -75% Steam sale, which came around Christmas. That hit and I had to try it out.
For a first game with it, my focus will naturally be the new religion system. I've read very little about it. The obvious civilization to pick is Boudicca of the Celts, who get an early faith bonus for any city next to a forest, so can start on religions far sooner than anyone else. Emperor difficulty feels about right, and Oval map has always been kind of randomly one of my favorites for no real reason.
Here is the starting save if anyone wants it.