My picks are the US, China, and Russia. North Korea, Saudi Arabia, and Israel just don't have the size or as much influence to match the other three.
Now while I don't think the US is as bad as the other two in some ways, like the US is probably not going to invade an modern industrialized nation like Ukraine (although the US will invade just about any third world country if it feels like it) or at least if it does it will have a semi-nonsensical reason rather than a completely nonsensical one like Russia or China would use, the US meddles in every little thing in the world for it's own benefit. It doesn't do it for mostly altruistic reasons like it would have people believe.
Russia and China are like a more ruthless, authoritarian, amoral version of the US that's not as powerful as it, at least not yet in the case of China. Unlike the US they don't even bother to pretend like they are doing anything for the right reasons.
North Korea and Saudi Arabia might be the two worst nations on the planet when it comes to how they brutalize their own people. Saudi Arabia gets away with too much and has too much influence due to oil, and North Korea has both nuclear weapons and the most batshit insane leaders in the world in one package.
I don't in any way give Israel a pass. I don't give a damn if they are surrounded by people that might be worse than them, or if they are technically a "democracy". That's not how it works. Countries don't magically get karma points to spend to do terrible things because of something else they might have done that was good, and they treat Palestinians like dogshit. South Africa rightfully got demonized for it's apartheid country and human rights abuses. I don't know why Israel gets a pass. Not to mention that it's creation was one of the stupidest things the modern world has ever done. The holocaust was terrible, and the ancient Israelites whom modern Jewish people have actual little link to other than religion, were screwed over, but neither of that justifies just kicking out people that have lived their their whole lives.
I would even go one step further and say by their own religious teachings they supposedly follow they have fallen so far and treated other people so badly they should consider themselves proven to not deserve any land there just by what has become of the content of their character and what their actions say about the country as a whole. It's ironic considering all the times in their religious writings God pretty much let the Israelites get kicked to the curb by some other people for their sins, and yet they don't seem to care or learn.