Well, I'm no longer obliged to "bear witness" for my gods -- I'm a pagan now. And I say so when anyone asks, but ...
If I lived some place where it wasn't safe to be an "odd" religion, and I had to pick something on official forms, I'd put down whatever religion most people belonged to. Here in the west, few members of the major religions take them seriously; it's common for lifelong church members never to go to church, but still identify themselves as such.
GentlyFeral