I'm not a big conspiracy theory person. Not because "they" aren't evil enough to do this stuff, but because I've interacted with the government too much to believe they have the competence to pull off and cover up these huge, elaborate schemes.
So for me to even entertain a conspiracy theory, it needs to:
- involve few enough people that it isn't absurd to think of them keeping their mouths shut, and
- be of some nature that would prevent/discourage any intrepid journalists from figuring it out.
That's one of the reasons, for instance, that I think 9/11 trutherism is so stupid: the sheer number of people who would have to know and keep quiet makes it completely unbelievable before you even get to any of the substance.
Anyway, I will throw out two things that are kinda conspiracy-ish, one that I absolutely believe and one that I would accept without much convincing.
I absolutely believe that the Israeli government operates a rogue nuclear weapons program, that high ranking officials in the US government (Democrats and Republicans) know for a fact that it exists and have repeatedly lied to the American people and the world to cover it up, and that the U.S. government has murdered people and threatened war against other Middle Eastern countries in furtherance of a concept of a "nuclear-free Middle East" they know Israel has already forever ruined.
It would not take hardly any convincing to get me to believe that Osama bin Laden was taken alive from that compound in Pakistan and spirited away to some Obama torture site somewhere.
I can't think of too many more. The government is just so bad at covering up its evil deeds. And these people are so rarely held accountable for doing evil out in the open that there's barely an incentive for them to hide anything. Everyone in this country will accept any atrocity committed by their own party, and a bunch of them will accept any atrocity committed by ANY party if it's the military, natsec, or law enforcement machinery doing it.