Hinduism is 90% my religion since the #1 research tech I pick is Polytheism. The rest of the 10% times is when someone else beats me to it. Then it is Judaism, and it's hard to beat me to Judaism since I go straight to it(since I got polytheism anyway, but failed, Masonary --> monotheism).
why?
I play on hard difficulty and the +Happiness religion gives is important.
Since Christianity and Islam come too late, I can not wait to get them. Even if I find these religions its a waste to Convert to a different religion for many reasons. Mainly because I love organized religion and already all my cities ahve Hindu or Judaism in them. Or, the Anarchy if am not spiritual. Besides, it doesnt matter. Unless I need to fix my standings with other civilizations IF my religion is vastly hated.
Why not Budhism?
Because I pick Polytheism and if I dont get that I definitely wont get Budhism either. But why I dont start by picking Budhism first? It's because if I pick Poly, and fail, Then Monotheism is so easy to get. So, it's kind of if I pick Poly and fail I still have another chance to get Monotheism.
There is some very rare chance that I dont get either Hinduism or Judaism, so it is Christianity. Unless I'm really really behind in tech, I do get islam with the help of a great priest.