I already did a whole post about scientology and what a cult is, they are both on my page if you want to click my name to read them. This blog will just be highlighting some other famous cults.
Heaven's Gate was talked about on the news when I was younger and I think even Oprah did an episode on them. It was a cult of people who believed that the world would be recycled and that a big space ship would rescue them earth during the process. They believed that the way to get to the ship was to commit suicide. So the night before the earth was going to be recycled they went to a house that the leader (Marshall Applewhite) rented and ate poison. They all got into bed that was provided for them with bags over their head in case the poison didn't work. The leader was among those who died. At least Marshall went down with them and just wasn't a crazy guy who wanted people to die. Before he died, Marshall had recorded messages and I'm sure you can find them somewhere on YouTube or something.
The next cult that was famous in the past but got press recently thanks to the leader trying to get married and then dying. That cult is the Manson family and they weren't actually a family but they all looked after each other and stuck together like families usually do. The family was led by Charles Manson who was confused with Marylin Manson after his death recently. The family went on to kill at least nine people and Charles was predicting a race war. I think he wanted to start one, too, on some level.
The Children of God is one of the top 10 most notorious cults. The reason this is because the leader of the cult, David Berg, took something sweet and innocent like teens for Christ and perverted into something more cultish and wild. David exploited young people to accomplish his goals but the group was plagued with reports of sexual violence, incest, and brainwashing. The group was showing the world one message but in reality, it was basically a child sex ring.
The 10 Commandments cult was started by a preacher and a prostitute. None of the members were allowed to speak or have sex—if you did, then you will be asked to leave or you would be killed. Then the leader had a prediction for the end of the world when it didn't happen, the followers would question their leader. He later told them it was a different day and that virgin Mary would come to start the apocalypse. Leading up to that day, the leader was preparing himself and the group for it. While waiting for this day, if anyone questioned the leader, they would be sentenced to death. Then on the day, he put gasoline on them saying it was holy water then locked them in a building and set it on fire. Among those in the building was the leader.
The People's Temple was one of the biggest with 5,000 members. It was started by Jim Jones who wasn't really into religion but wanted a way to promote Communist theory and thought religion was the way to do so, thus the invention of the people's temple. There were allegations of child abuse. The group was a mix of Christianity with communist and socialist ideas with a focus on race equality. It all came to an end when the leader told the members to commit suicide 918 people died in 1978.
Hope you enjoyed this overview of famous and crazy cults. These always interested me. Do more research if you want to, this was just an overview.