Though I think they're all equally nonsensical, I suppose it would have to be:
Judaism
Christianity
Islam
why? Simple; the amount of nonsense packed into each religion gets larger in volume as they progress;
Judaism is essentially the Old Testament of Christianity, so Christianity has double the nonsense. Islam then steps in and says that "yeah Christians had the right idea, but they messed up along the way, so here's the Quran" -- TRIPLE the nonsense.