Every major religion has it's fanatical extremist. The difference is that every one other than Islam doesn't have huge segment of the people that practice that religion that act that way, at least not for hundreds of years now. With the other religions they are an extremely small percentage and they are looked down upon by the vast majority of people that practice it. I don't see too many Christians, Jews, Hindus, or Buddhist dance in the streets for the death of their enemies. I don't see too many of those religions other than Islam directly control totalitarian regimes or governments. I don't see too many of them other than Islam calling for a Jihad every other day. Suicide bombers and terrorist don't seem to be a problem for the other religions either. The other religions don't have people in power actively destroying works or art made of the other religion or make it illegal for people to practice other religions. With the other religions it's not like a great many people help or look the other way when the extremist go to work.
As far as how bad some religions are Islam is definitely worse than the others. Pretending it isn't true isn't going to change that reality.
religion's done as much harm as good, but yeah kind of like what i said before all religions have sects of the "extremists" they make up a minority, they in NO way represent the face of their religion. i have friends who are muslim, i was raised christian, i have jewish heritage, of all these religions i have had no encounter with an extremist
as for islam being the worst i disagree, but you'd better run like hell because it's the worlds largest and fastest growing religion