Without question, Potholer54. Sure, Thunderfoot wins by sheer volume, but video for video, Potholer's are more succinct and deal directly with explaning scientific information for the layperson. He does deal with religion in disproving creationism.
Though he's loud, I like The Amazing Atheist. Sure, he goes to far some times, but most of the time the rest of the world doesn't go far enough. He makes some very good points, and is often very funny.
Also, KingHeathen and Agnosticman both give great philosophical arugments against religion. They should, since like me they are both former fundies.
Obviously VenomFangX, despite his recent "turn around" in light of the purjury scandal. He blatantly has lied to people while professing Christian values. Hypocrite.
Nephilumfree . . . really makes me think he enjoys molesting children. I'm sure he doesn't . . . he just looks like he does. Also acts so superior and arrogant.
Jezuzfreek: I'm not too confident putting him down here. He pisses me off, because every last one of his arguments can be boiled down to "because the Bible says so". He never gives a reason WHY we should believe in the Bible, besides saying "it's God's word", which he never says WHY we should think it is God's word.
On the plus side, he doesn't censor, and at least is consistent with his beliefs for the most part. He sticks to his story, unlike Venom. He isn't a hypocrite, he's just the epitome of a Bible thumper.
Then there is Yokeup. Take the Bible thumping of JF, the slimy nature of Venom, and the creepyness of Nephilumfree, and you get Yokeup. He's just awful, bigoted, and is the epitome of everything bad with Christianity.