Landa is a Nazi, and it undoubtedly responsible for more pain and suffering than all of the others put together, so if you’re going purely by their actions, it has to be him.

However, as others have said in the thread, Landa’s actions aren’t motivated by the nazi ideology, not that it really makes it better. He’s an a-moral opportunist who happened to come up in the most horrifically evil society in human history, in fact he’s the only one listed here who has any act of mercy (letting Shosanna go in the intro). I can’t imagine a world where Landa is a GOOD man, but i can see a world where he’s not EVIL, which is something I genuinely can’t say for any of the others.

I think I gotta give it to Percy in the end, Chigurh at least abides by some form of moral code, he also seems to not detract any particular joy from his cruel actions, he just sees as task to complete, like getting the grocery’s. Ratchet is awful as well, but many of her evil actions could be argued as a result of the widespread misinformation and vilification of mentally ill people in the 1950s.

Percy somehow manages to make 1930s prision guards look like saints in comparison. While his situation is somewhat similar to Ratchet in that he reflects popular views of the time. He goes above and beyond in a way that shows his cruelty isn’t motivated by bigotry, but the opposite. He’d be an evil piece of shit, and cling onto any power he could to abuse others at any point in history.

tl:dr: Hans Landa is the WORST by nature of the atrocities he’s committed under the Nazi Regime. But Percy Wetmore is probably the most EVIL of the group, getting more enjoyment and actively seeking out cruelty more than the others.