There's no 'definite' list, because such a complex topic can be pillpulled ad infinitum into polemic chunks which you can then relativise, belittle, twist and so on. To even be able to counter this you have to understand several key factors:

• In a rational, scientific debate, you'd expect a robust theory that can be falsified. That is not the case at all. The theory has even been adjusted so many times with new facts handwaved ad hoc into the narrative
• It is the bedrock of our western world. Even more, mentioning Hitler, the Shoa etc increased a lot over the last decades.
• Most people are not familiar with the main assertions by scholars (of both sides) at all, they basically think the Hollywood version is true, as confirmed by thousand of experts

That said, a few kew points that are good entries into research

• probably all the meta atrocities we grew up with (soap, weird experiments etc) are more or less proven to been hoaxes or are ignored by mainstream because of their shoddy evidence
• the N.trial
• all aspects of the death-logistics on every level are bizarre and honestly easy to shut down
• there's not one reliable witness piecing everything correctly together.
• most witnesses are unreliable because most of what they say was outlandish and the whole story is woven together by taking unconnected details from a handful survivor stories and mixing them up
• many survivor accounts were fraudulent
• the five million statistic was apparently made up by Wiesenthal, as stated by Bauer
• there has been a lot of propaganda going on during ww2. The soviets were the worst of them all, naturally with a huge number of doctored photos, reports coming out as 100% false late after the war
• no higher ups "believed" the story after the war. Most people, too, didn't believe becaue they still knew the ww1 propaganda was debunked after the war

What remains are a couple of factoids like the "Posen Speech". Not much to chew on, frankly. Then there's quagmires like demographics, "was there a chimney?". Not worth going into.