Sprinkler lady aside, I'm going to go out on a limb and say that truthers are most def. the craziest.
I recently had a long conversation with an individual that I generally consider to be intelligent, rational, and not the least bit crazy after he made me watch "Zeitgeist". It practically made me go crosseyed with the gross stupidity of every "truther" argument. None of them hold up to serious big-picture scrutiny, but people cling to them like a talisman. Even presumably rational intelligent people. And also Charlie Sheen: http://www.prisonplanet.com/twenty-minutes-with-the-president.html (Although honestly, I'm hoping that his "truther" stance is really just a long, elaborate, and not all that funny practical joke)
The best part of the "Truther" movement is George W. Bush's quantum status. He is, all at once, the most deviant, brilliant, evil master mind this world has ever seen AND the most incompetent, idiotic, mouth breathing, can't-even-dress-himself-in-the-morning human being to ever walk the earth.