I haven't been watching the religious debates on youtube, but around 2008, I was into it. There were a few I still remember to this day.
Geerup:
Large Ham creationist, apologist, and conspiracy theorist. Aside from the standard apologetics, he would go on many rants on how atheists are taking over. He made a series of videos called "Godless Guy" where he would speed up his voice (like Fred) to create a straw atheist. He was the one who replaced venomfangx, but I don't recall any recent videos from him. Overall, a real nutty and kind of scary guy.
Sablechicken: Sister of geerup. I don't remember much about her other than that she had quite the persecution complex.
Yokeup: Seemed like a nice guy at first. Just some southern guy and his wife going around spreading the good news. He was friendly toward atheists and seemed very humble and down to earth... until his true colors showed. He would make "friendly" jabs at people, calling them "knuckleheads". Like most fundies, he thought God gave him the authority to tell others what to do. Eventually, this went to his head and he started alienating Christians as well as atheists. He eventually shut down his channel after he realized he was youtube enemy number 1, but I think he has other channels somewhere.
He also got into politics and boy was he a "knucklehead". He thought
George W fucking Bush was the best president of all time! He also made a video calling Obama evil and saying that Palin and Mccain were "people of God".
His wife is also lesbian, or at least she was until she was "cured" of her homosexuality by Jesus. Sadly, she just seemed to go around being his yes woman. Some have suspected that yokeup is a wife beater (wouldn't be surprising, I knew someone just like him who was a domestic abuser). But it's hard to tell what's going on in their head.
Lucaslabrador: British Calvinst. I haven't watched much of his videos, but I remember he was very anti feminist.
Jezuzfreek777: The least insane of the bunch. He was just a typical evangelical Christian, enthusiastic with what he was teaching, believed in traditional values, and had that "hip Christian" persona. He was capable of reasonable thought and could be a nice guy. On the other side of the coin, he had some real
jerkass tendencies. He was one of those people who thought that if people had different beliefs, that they were probably going to hell. He was also a Republican and after the election results, he made a video saying that although Mccain lost, they had a victory with prop 8. Yes, he considered denying people the right to marry a victory, proving him to be a total asshole. I think he still makes videos, but honestly, I can't get a minute through them without wanting to throw up.
Tony48219: A tragic case. He was a black guy who's videos were profanity laced tirades against feminists, white people, atheists, and a whole list of other people. Sadly, he became famous when he
got ahold of a gun and killed a fellow classmate before turning the gun on himself. Venomfangx: I think most people know about him. I'd best discribe him as Sheldon Copper (from the Big Bang Theory) if he was a fundie creationist. He was EXTREMELY arrogant, but using extremely bad logic. He proved what an asshole he was in one video when he gave his response for why god doesn't heal amputees "we don't deserve to be cured, we deserve to die". There are many other instances of his assholish behavior, but I don't think I need to go further.
Lastly...
Inmendham: A rare atheist fundie. He lived up to the "atheism is hopeless" stereotype. He had a lot of ideas about what to do to improve humanity (many contradictory), but for the most part, he seemed to think that we would all be better off dead. He was even nihilistic enough to encourage suicide on many occasions. Like most online lunatics, he had a real persecution complex and was a real asshole. He filed many many frivolous lawsuits against people on youtube (and youtube itself). He was always dissing youtube and google because they took down his videos (a reasonable complaint, but he acted like they were personally out to get him) and overall had a real negative outlook on life. Seems like a smart guy, but damn is he one crazy mother fucker.
I think he still makes videos on 10 different channels. Though I haven't watched any recently because his content is so depressing and nihilistic that I feel drained afterwards (though his profanity laced tirades against google are always entertaining).
I don't know how many of these people are still on now, but those were the main crazies when I was watching the atheist/theist debates.