Probably Islam if for no other reason than it is the slowest to become "modernized". This being a majority taking a more moderate approach to it and not following strict rules, and no, I am not assuming Islam is all Sharia Law. But just as Protestantism and Catholicism once were I'd say a larger percent of Islamists are extremists than with Christian ones even if only slightly. I of course have no evidence to prove this statistic so feel free to prove me wrong.