Scientology is the most evil. It was born out of corruption and is the only major religion that you have to pay for to get "enlightenment". It breaks up families and does horrible things to people that leave and/or disagree with them publicly.
Mormonism is just a con man's made up religion. It's basically the bible that we all know, but based in North America. Polygamy wasn't in the religion until he got caught banging his best friend's wife. Then he claimed the angel told him to be polygamous and everything was alright then.
Islam, if you put it into chronological order, is basically Mohammed's desires. It's pretty telling that the quran was changed and made into the shortest to longest verses, rather than the original chronology based text. We could take any autobiography and convert it into a religion, as the muslims did.
Judaism uses the Cain and Able story to separate themselves from the Canaanites which they were once part of. It just goes downhill from there. They were never slaves in Egypt. They never wandered the desert. They have an extremely bloodthirsty history, as well.
Christianity is very strange. Nothing except the stuff written by Paul is from the person it's claimed to be by. Paul was a paid christian killer until he meets Jesus' ghost, then he decides to take over the religion which means eliminating a few more of the leaders. Jesus know what the prophecies were and he made them happen. As an example, when going into Jerusalem, he told his buddies to go steal a donkey and a purple robe for him because that's what the prophecy said. There were 2 Bethlehems, one in the north and one in the south. For about the first 600 years, the Bethlehem in the north was Jesus' birthplace. I don't know what exactly happened by now he was born in the southern Bethlehem. The mosaic floor from the original church (the one in the north) marking his birth place is in the wall at Tel Aviv airport.
Sadly, I'm not too clued in on the eastern religions and their beginnings.