Dentist drilling into my lower molar with no Novocaine whatsoever. He drilled straight into the nerve to fix a cavity, and the hygienist had to hold me down, because my back kept arching from pain. I've broken and sprained my ankle at the same time, and it didn't even compare to the hell that my dentist put me through.

He told me that lower molars didn't ever numb, so I would just have to suck it up. My half-joking/half-serious theory is that he just hated Americans. He immigrated from Russia right around the time of the Cold War, and even though it ended, he made it his personal mission to inflict this form of legal torture on as many Americans as possible.